JOURNAL OF THE ROYAL MICROSCOPICAL SOCIETY, DECEMBER 1892. .

TRANSACTIONS OF THE SOCIETY.

XI.-Alga of the English Lake District. By WM. WEST, F.L.S. (Read 16th Nouember, 1892.) PLATESIX. AND X. SEVERALvaluable papers have already appeared in this Journal relating to this subject; there was one by Mr. Bissett in 1184, and since that, two by Mr. A. W. Bennett in 1886 and 1888. As I have practically made collections yearly since 1879 from numerous localities, I am enabled to offer the following contribution to the already large

EXPLANATION OF PLATES. (Explicatio iconurn.) a, a', a" = front view (a fronte visa). b, b' = vertical view (a vertice visa). C = side view (a latere visa). d = basal view of aemicell (a basi visa). PLATEIX. Fig. 1.-Closterium abrupturn sp. n. x 520. ,, 2. ,, turgidtun Ehrnb. var. decoraturn vw. n. Cell membrane x 830. ,, 3.--Sphsrorosrna vertebraturn (BrLb.) Ralfs formit minor West. x 520. ,, 4.-Spondylosiurn pyqrnamrn (Cooke) West var. compFessum var. n. x 400. ,, 5.-Micrasterias denticulutu Ureb. vw. subnotatn var. n. x 220. ,~6.-Euastrum Finale (Turp.) Ralfs vai-. retusum var. n. x 520. ,, 7.-Peniurn sp. x 520. ,, 8.-Co~rnariurn obcuizocttum West forma. x 520. ,, 9.-Ermstmm eleguns (Breb.) Kdtz. var. ornutum var. n. x 520. ,, lO.-Cosmariurn morsum sp. n. x 520. I, 11. ,, coarctatum sp. n. x 528. 1, 12. ,, Holrniense Lund. var. integrum Lund forma. x 400. ,, 13.-Closterium oblusum Breb. forma. x 520. ,, 14.-Gosrnariuwa MenegkdrLi Br6b. forma (c. zygosp.). x 520. ,, 15. ,, obliquum Nordst. forma minimu. x 520. 9, 16. ,, pseudarctoum Nordst. x 520. ,, 17.-Ezzastrarn erosurn Lulid. var. notabile var. n. x 520. ,, 18.-Cosrnariurn su7)punctuZaturnNordst. var. Boerqesenii West forma. x 520. ,, 19. ,, cyclicurn Lund. var. nngulatum West. x 520. 9, 20. ,, RegneZlii Wille forms. x 520. Y7 21. ,, pseudutlanthoideum sp. n. x 520. ,, 22. ,I subcylindricurn sp. n. x 520. 1892. 3C 714 Tralzsactioias of the Society. number of species on record. No species is here recorded for any locality in which it has been found previously; but almost every species recorded in the paper of Mr. Bissett and those by Mr. Bennett has been again seen from the same locaiities. The gatherings covered most of the Lake District proper, and Mr. W. H. Youdale kindly made a fern gatherings for me from near Cockermouth, Embleton, Crummock Water, and Bassenthwaite Water. There are 589 species and 78 varieties in this paper, one genus, 21 species, and 23 varieties of which are here described for the first time, and in addition to the latter, there are 27 species and 10 varieties recorded as new to the British Isles (prefixed by an asterisk). In the preparation of this paper-as in former papers-I have again to acknowledge the invaluable help of my son, G. S. West (National Scholar in Biology), who also assisted in making the collections from near Bomness. The locality " Bowness " includes pools near there with Nymp7ma alba and Utriczclaria, small pools with the latter on Brant Fell, and other suitable places as far as Lindeth where many gatherings were made.

Fig. 23.-Cosmarizr,m cymatonofophorum sp. n. a, X 530 ; a', a", b, et c x 520. ,, 24. ,, suprcispeciosuin Wdle vnr. emarqinatum vm. n. x 520. ,, 25.--Sta?~rastrum arcuatum Nordut. subsp. subanicula subsp. n. x 520. ,, 26. ,, Brdissonzi Arch. vnr. brevispinum vnr. n. x 400. ,, 27.-Arthroclesmus qlaucescens Wittr. forma conwexu West (c. zygosp.). x 520. ,, 2X.-Stcmrasfrum ellipticlcm sp. 11. x 400. ,, 29.-Cosrncirium subcapitulum sp. 11. x 520. )) 30. ,, Clqxydm Nortlst. x 520. ,, 31.- Cosmarium ochthod~sNordst. var. amffibumvnr. n. Verruca x 530. ,, 32. ,, mzerovphhcturn Nordst. x 520. ,, 33. ,, zlexafum sp. n. x 520. ,, 31.--Sfaurastrum aezcostatzcm Bre'b. subsp. producturn subsp. n. x 520. ,) 35. ,, polyinorphum BrBb. Tar. munituin var. n. x 520. ,, 36. ,, grcicile Hnlfs var. eoronulatum Boldt. f. 3-gona. x 520. ,, 37. ,, Pseudosebaldi Wille var. simp7icior var. n. x 520. ,, 38. ,, vestituin Ralfs var. semivestdurn var. n. x 520. ,, 39.-Dimorphococcus lunatus A. Br. x 520. PLATEX.

,, 40-42.-Cylindrocapsa conferta sp. 11. x 520. ,, 43-46.-Tetracoccus botryoidas gen. ct sp. n. x 520. ,, 4748.- 3, 7 ,, Two groups of four cells. x 830. ,, 4D.-Nephrocytium lunafum sp. n. X 520. ,, 50 -Selenastrum obesicrn sp. n. x 520. I, 51. I, ,, ,, Two separate cells. x 830. 71 52. ,, ,, x 520. ,, 53 -Tetra&dron gigae (Wittr ) Hansg. var. mamillah var. 11. x 520. ,, 54.-Trochiscia uncinata sp. n. x 520. ,, 55 -Chlorococcum regulnre sp. n. X 520. ,, 56.-Oocystis elliptica sp n. x 520. ,, 57.-Schizoeh7amys delicatula sp. n. x 520. ,, 58.--Lyngbya subtile sp. n. x 530. ,, 59 & 60.-Chroococcus giganteus sp. n. X 520. ,, 61-03. ,, schizodermaticus sp. n. x 520. ,, 64.-Cffilnsfrum sphariciirn NLg. x 520.

Alp?of the Elzglish Lake District. By Wqn. West. 715 The following contractions are used :-B. for Brother's Water ; Bn. for Bowness; Bo. for Borrowdale; Bt. for Blea Tarn, West- moreland; C. for Bogs around Cockley Beck (Lancashire); H. for Helvellyn; Hk. for pool, Hawkshead to Yewdale; Hp. for Harrop Tarn: L. for Loughrigg; R. for Rydal Fell; S. for Scandale; SIT.for near Skickle Tarn ; W. €or Wastdale and Wast Water. ALGAZ. Class FLORIDEB. Order HELNINTHOOLADII. Genus Batracliospermwn Roth. B, 1mo~2iformeRoth, Threlkeld. Order LENANEACEB. Genus Lemamea Bory. 5.JEuviatiZis Ag. H., Foot of Bow Fell, near Angle Tarn, L, torulosa (Roth.) Ag. S. Class CONFERVOIDEBHETEROGANB. Order COLEOCHBTACEB. Genus Qoleochzde BrAb. 0. scutata BrBb. B., R., Crummock Water.

Order ~~DOGONIACEB. Genus Bulhckte Ag. ; PringsB ? B. setigeru (Roth.) Ag. (sterile). Bn., S., B., Bassenthwaite Water, Grisedale Tarn." B. yectamgulavis Wittr. L. Genus G9clogoleium Link ; Pringsh. CE. cryptoporurn Wittr. Blea Tarn in Borrowdale. var. udgare Wittr. Forma cellulis longioribus. Bn. CF. Itzigsohnii De Bary. Hp. a. unddatum (BrBb.). A., Br., S. CE. calcareum Clew. Bzl. Class CONFERVOIDEBISOGAMB. Order CONFERVAGEB. Genus Corzferva (Linn.) Link ; Wille. "C. Wittrockii Wille. Lat. fil. 12-13 p. Bo., Hawkshead. "6.Raciborskii Gutw. Bassenthwaite Water. 3c:: 716 Transactions of the Society. C. bombycina Ag. forma genuina Wille. Bn., H., Deep Dale, Angle Tarn. forma minor Wille. Common. C. Jloccosa (Vauch.) Ag. B., H., Crummock Water. Genus Cladophora Eiitz. C. crisyata (Roth) Kiitz. Embleton. Genus Chatophora Schrank. C. elegans (Roth) Ag. R. Genus Draparnaldia Bory. D. gzomerata (Vauch.) Ag. Bn., Crummock Water. D. plumosa Ag. Buttermere. Genus Xtigeocloniurn Kiitz. 8.fastigiatum (Ralfs) Kiitz. Crummock Water. Genus Microthamnion Niig. M. uezator Cooke. Hk. Genus Aphaltochzte A. Br. A. gZobosa (Nord.) Wolle. forma minor Nord. Diam. cell 10-11 p. Bn., Hp., R., Sk. Order ULOTRICHACEB. Genus Ulothriz Eiitz. U. parietina Eiitz. Sk. U. tenerrima Kctz. Langdale. Genus Schizogonium Kutz. S. murale Eiitz. H. Genus Hornaiscia Aresch. H. moniliformis (Kutz.) Rabh. S. H. zonata (Web. and M.) Aresch. B., Crummock Water. forma major. Lat. cell. 47-50 p. H. H. qualis (Kiitz.) Rabh. var. catenteformis (Kiitz.) Near Cockermouth. Class CONJUGATEB. Order MESOUARPEE. Genus Mougeotia (Ag.) Wittr. M. nummdoides Hass. Scarf Gap Pass, Kirk Fell. N.recwrvus (Bass.) De Toni. Bo., Bassenthwaite Water. Algz of the English Lake District. By Wm. West. 717 ill. parvula Bass. forma sporis rotundo-ellipticis. Long. spor. 15-16 p; lat. spor. 12.5-14 p; Bassen- thwaite Water. M. padrangdata Hass. [M. quadrata (Hass.) Wittr.1 forma minor. Crass. cell. veget. 7-7 5 p ; diam. spor. 28-30 p. Bassen- thwaite Water. M. viride (Kiitz.) Wittr. Bn. M. gracillima (Hass.) Wittr. B., H. (at 2400 ft.). ? M. elegam%du Wittr. Crass. cell. veget. 5 p (sterile). Bn. All the species of Mougeotia were in abundant conjugation except the last. Order ZPGNENACEB. Genus Sirogonizcm Kiitz. 8.sticticum (Eng. Bot.) Kiitz. H. Genus Xpirogyra Link. S. tenzcissima (Haw.) Kiitz. Forma cellulis fructiferis subtumidis. Lat. cell. fruct. 27-30 p; long. zygosp. 60-64 p; lat. zygosp. 23-25 p. Bn. This approaches var. pbna Lagerh. (Contrib. F1. Alg. del Ecuador, p. 7). S. fEuvescens (Hass.) Kutz. forma. Lat. cell. veg. 14-16 p ; long. zygosp. 53-55 p ; lat. zygosp. 22-28 p. Esthwaite Water. 8.gracilis (Hass.) Kutz. Forma zygosporis solum diametro It-plo longioribus. Lat. cell. veg. 19 p; lat. cell. fruct. 39-41 p ; long. zygosp. 42-44 p ; lat. zygosp. 27-30 p. Bn. S. varians (Hass.) Kiitz. Black Sail Pass. Forma cellulis sterilibus minoribus et zygosporis diametro l&-plo longiori bus. Lat. cell. ster. 21 p; long. zygosp. 34 p; lat. zygosp. 25 p., KO. *S. Lutetzana P. Petit var. MINOR var. n. Tar. duplo minor quam forma typica, eellulie vegetativis diametro 8-plo longioribus ; zygosporis cylindrico-oblongis, diametro 3-4-plo longioribus. Lat. cell. veget. 19 p; long. zygosp. 50-63 p; lat. zygosp. 18-19 p. Bo. S. nitida (Dillw.) Link. Bn. Only occasional sygospores. 718 Transactions of the Society. Genus Zygnema Ag. Many sterile species, from various localities, were seen, but none were observed in conjugation. Genus Debarya Wittr. D. glyptosperma (De Bary) Wittr. R. Order DES~KIDIACEAL Genus Gonatozygon De Bary. G. Ealfsii De Bary. L,, B., R., C., Brandreth. G. Brebissonii De Bary. L., B., R., S,, Brandreth, G. minuturn West. Bn., Stye Head Tarn, "G. Kjellmani Wille. Forma minor et recta. Long, 58 p ; lat, 6-6 * 5 p. Bo. Genus Sphzrozosma Corda, 8. vertebraturn (BrBb.) Ralfs. B., R., Bassenthwaite Water, forma minor West (Addit. to the Freshw. Alg. of W. Yorks. in Naturalist, 1891, p. 244). Fig. 3. Hp.; Sk., B.. R. 8. exenvaturn Balfs. Frequent. S, granulatuni Roy et Biss. Bn., W. Genus 8po.nclyZosizcrn BrBb, 8.pulelwlluni Arch. Hp., Grisedale Tarn. S. pygrnmm (Cooke) West (Contrib. Fr. Wat. Alg. of W. Ireland, p. 116). var. WIUPRESSUM var. n. Fig. 4. Var. cellulis subquadrangularibus, compressis ad polos, Long. cell. 5.5-6 p ; lat. cell. 7 p ; lat. isthm. 2 * 5 p. B, Genus Oiaychonema Wallich. 0.jiliforme (Ehrnb.) Roy et Biss. Bn. Genus Hyabtheca Ehrnb. E.dissiliens (Sm.) BrBb. Very frequent. At 2400 ft. on Helvellyn. It was seen with zygospores from Harrop Tarn, Bowness, Loughrigg and Hawkshead. forma bidenfuZa (Nordst.) Boldt., B., Bn., L., Sk. var. hians Wolle. Bt., Sk., C., Hk., Lake Side. *var. tatrica Racib. (Nonn. Desm. Polon., p. 8, t, xiv. f. 5). Long. cell. 20 p; lat- 16-16.5 p. Hk. 11. IJ~UCOSCZ(Dillw, 3) Ehrnb, B., R., 8, Alga! of the English Lake District. By Wrrz. West. 719 Genus Gynmoxyga Ehrnb. G. moniliformis Ehrnb. Hp., W., Sk., C., Hk. Genus Desnaiditm Ag. D. cylindricum Grev. L. D. Xuurtzii Ag. W., B., R., Hk.,Deepdale, H. (at 2400 ft.). D. nptogonum BrBb. L., S. var. acutius Nordst. Bn. Genus Plezcrotzniunt Nig. P. coro-izatum (BrBb.) Rabh. B. var. .~zodulosuat (Brdb.) West. [Docidium coronatunt BrQb. var. nodulosum (Brdb.) Roy]. Bo. P. Ehrenbergii (Ralfs.) De Bary. Frequent. P. cZnvatum (Kutz.) De Bary. B. P. maximum (Reinsch) Lund. var. OCCIDENTALE var. n. [ P. maximum West (Contrib. Freshw. dlg. of W. Ireland, p. 119)]. Var. ad formam typicam similis sed ter minor est. W., Bn., Hk. This is 24 to 3× smaller, but in form it agrees exactly with the species described by Reinsch (Alg. F1. Yon Mitt. Frank., p. 181, t. 12, f. iv.). It is quite distinct from P. Ehrenbergii (Ralfs) De Bary. P. truncatzcm (Brdb.) Nag. Bo. Genus Closterizcm Nitzsch. C. didymotoczcm Corda. C., Ilk. (7. ABRUPTUN sp. n. Fig. 1. C1. angnste lanceolatum, circiter decies longius quam latius, levo curvatiim, latere ventrali non (vel levissime) turnidum, sensim zequaliter attenuatum utrimque in apicem truncatum ; membrana luteola et non-striata ; pyrenoidibus 8-10 in mica aerie. Long. 127-156 /I; lat. ad medium 12-15.5 p; 1at.apic. 6-7 p. C., Hk.,Esthwaite Water, Ennerdale. This is similar in shape to some forms of Cl. imtermedizcin Ralfs, but differs in its much smaller size and in its membrane not being striolated. forma PUNCTATA. Forma membrana irregulariter punctata. C. 0.obtusuin BrBb. Forma apicibus subtruncatis. Long. 41 p ; lat. 7-5p. Fig. 13. H. C. lzina7n (lfuller) Nitzsch. Frequent. 720 Transactions of the Society. 0. lanceolatlcm Kutz. Bo., Bn., near Cockermouth. C. turgidurn Ehrnb. Bo., C., Hk. Long. 750-791 p ; la€. 66-75 p. Tar. DECORATUN var. n. Fig. 2. C1. striis prope medium punctorum factis, apices versus irregulariter punctatum (nec in lineis). Long. 510 p ; lat. 43 p. Bn. 0. pradongurn BrBb. Bn. C. strigosum Br6b. S. C. gracile Br&. Hk. C. EiLrenbergii Menegh. Bo., H. (at 2400 ft.), Deepdale, Crum- mock Water, Vale of Newlands. C. nzonilzyerurn (Bory) Ehrnb. H. (at 2400 ft.), near Cocker- mouth, Vale of Newlands. 0. Jenneri Ralfs. Bo., L., Hk., Brandreth. C. Leibleinii Kiitz. B. C. Diane Ehmb. Frequent. Occurs up to 2400 ft. on Helvellyn. C. parvulum Xig. Hk. C. Venus Hutz. B., L., Bn., Hk. C. Cynthia De Not. Hk. C. Arckerianum Cleve. Bn. C. costaturn Corda. W., S., B., Deepdale. C. striolatum Ehrnb. Frequent. Tar. orthonotum Roy. W., Grisedale Tarn. C. intermedium Ralfs. W., R., C., Grisedale Tern. C. angustatum Kiitz. Bt., C., Hk. C. juncidurn Ralfs. Bo., C., Hk., Brandreth. C. lineaturn Ehrnb. W., Hk. C. attenuatum Ehrnb. Hk. C. Ravsii BrBb. Tar. hybridum Rabh. Bn., L., Hk. Long. 600-616 p ; lat. 41-43 p. C. rostratum Ehrnb. Bn. (cum zygosp.), Derwent Water (cum zygo,sp.), near Blea Tarn. C. setaceum Ehrnb. W. C. Kutzingii Bre'b. Bt. (cum zygosp.), Hk. C. Cornu Ehmb. S., Bn., H.,Derwent Water. forma major Wille. Bn. C. acuttcrn Br6b. B., Threlkeld. C. Zinea Perty. B., Bn. Genus Penium Brdb. ; De Bary. P. nanrgaritacez~rn(Ehrnb.) BrBb. C. P. cylindrus (Ehrnb.) BrBb. H., Hk. P. spirostriolatum Bark. Hp., S., C., Hk. P,digitus (Ehrnb.) Br6b. Very frequent. Algs of the English Lake District. By Wm. West. 721 P. interrupturn Bra. Hk. P. closterioicles BaIfs. W., S., Hk., near Cockermouth. forma INTERRUPTA. Forma massa chlorophyllacea in partibus quattuor &visa. Long. 122-125 p ; lat. 24-26 p. Black Sail Pass. P. NavicuZa Brdb. Bo., Hp., W., L., C., Buttermere. Forma Wille (Ridrag ti1 Kundsk. om Korges Ferskv. Alg., p. 49, t. ii. f. 32). Bn., H., Langdale. P. curtum Brdb. forma nzinm Wille. H. forma minuta. Long. 22 p; lat. 10.5 p*; lat. isthm. 10 p. C. P. truncatum Ralfs. C. P. didymocurpum Lund. Long. 31-34 p ; lat. 13-14 p ; long. zygosp. 22-24 p ; lat. zygosp. 31-33 p. Hk. P. poZymorphum Perty. Hp., Hk., Buttermere, Grisedale Tarn, Scarf Gap Pass, Brandreth, Blea Tarn in Borrowdale. P. CZevei Lund. Long. 96 1.1 ; lat. 42 p ; lat. isthm. 39 p. Bn. P. cucurbitinum Bias. H., Trough at Ambleside. P. minutum (Ralfs) Cleve. W., Hk. P. sp. Long. 27-30 p; lat. 10 p. Fig. 7. Pike of Bliscoe.

Genus CylindrocystisMenegh. C. Brebissonnii Menegh. Very frequent. Zygospores seen from Stickle Tarn. C. crassa De Rary. H., H., Sk., Eirk Fell. C. dipZo.qpora Lund. Sk., Hk. Genus Tetmemorus Ralfs. T. Bre'bissonii (Menegh.) Ralfs. H p., Sk., C., Buttermere, Scawfell. Tar. minor De Bary. Hk.,Brandreth. T. grandatus (BrBb.) Ralfs. Common. f. minor Nordst. Sk. var. attmuatus West. Sk., Bt., Hk. T. Zavis (Eutz.) Ralfs. Common. Genus Spirolania BrBb. S. condensata Brhb. Bo., Ek. Genus Mesotaniurn Nag. M. micrococcum (Kutz.) Eirchn. Sk. M. miriJcum Arch. Sk. M. De Greyii Turn. Bn. 722 Transaciiom of the Xociety. Genus Micrusterias Ag. M. rnucronatn (Dixon) Rabh. Bo., Sk., Kirk Fell, Grisedalc Tarn, M. Crux-Melitensis (Ehrb.) Ralfs. f. punctulatn. Forma membrana irregulariter punctulata (subgranulosa). Bn. The punctulations cause the margin of this form to appear minutely papillate. M. Americana (Ehrnb.) Ralfs. Deepdale. M. angulosu Hantz-sch. C. ill. denticulata BrBb. Frequent. "var. alzgzcstosinuata Gay (Essai d'une monograph. des Conjug., p. 52, pl. i. fig. 4). L. var. BUBNOTATA var. n. Fig. 5. Semicellulae a vertice visae cum elevatione mediana latissime conica, lobi polari medio dentibus duobue parvis. Lat. 170 p; crass. 50 p. Bn. Compare with M. denticuluta var. notata Nordst. (Freshw. Alg. of New Zeal. and Austr., p. 29, t. 2, f. 13). 31. sotatu (Grev.) Ralfs. Bo., B., S., C., H. (at 2400 ft.), Deepdale. 112. Thomasiaiza Arch. C. N. rcidiosa Kalfs. Bn. M. apicidata (Ehrnb.) Menegh. subsp. $fin&&& (Ralfs) Nordst. Bn. M. papilliferu BrBb. Bo., Hk. M. truncata (Corda) BrBb. Frequent. forma punctata West. Bo., C. forma gramdata Racib. Hk. M. Jenlzeri Ralfs. Sk. var. simplex West. (M. Jenneri f. brusiliensis Boerg.) Sk. Genus Euustrum Ehrnb. E. verrucoszim Ehrnb. B., W., S., R., Hk. E. obZo?zgzcm (Grev.) Ralfs. Frequent. E. erassum (BrBb.) Kutz. W., C., Kirk Fell. E. veiLtricosuab Lund. Hk. E. pinnatum Ralfs. Hk. E. hunxerosu~zHalfs. 13t. E. afine Ralfs. Bt., B., C., Scawfell, Brandreth, Kirk Fell, Black Sail Pass. E. anqmllacezwa Ralfs. Bt., Hk., Brandreth, Eirk Fell, Black Sail Pass. E. insigne Hass, Frequent, Alga of the English Lake District. By Wm. West. 723 E. dide2ta Ralfs. W., B., C., Hk., H. (at 2400 ft.), Black Sail Pass, Deepdale. E. czweatum Jenner. Hp., C., Hk., Black Sail Pass, Scawfell, Kirk Fell. E. ansatum Ehrnb. Frequent. E. circulare Hass. H. E. sinuosum Lenorm. W., L., Hk., Bt. E, pectinatum BrBb. Frequent. E. gemmaturn BrBb. Hk. E. rostratum Ralfs. B., Hk. E. elegans (BrBb.) Kiitz. Very frequent. var. bidemtatum Nag. H., B., S., Hk. var. ORNATUM var. n. Fig. 9. Semicellulae verrucis sex ad medium, in seriebus trans- versis duabus, cum granulo intus extraque ad angulos inferiores ornate, etiam cum granulis binis prope basem incisionis polaris. Long. 47 p ; lat. 29 p ; lat. isthm. 8 p ; crass. 14 p. Ep., Sk., Bn. E. erosum Lund. Tar. NOTABILE var. n. Fig. 17. Semicellule lateribus bilobulatis, lob0 polari qnadrato- truncato, anguste vel sublate inciso, intra marginem granulis instructis, duo ad apicem, quattuor prope inciaionem, et unum supra medium ; a vertice visae angustiores quam forma typica, lateribus subrectis. Long. 31-33 p; lat. 20-21 p; lat. isthm. 46p ; crass. lop. H.,S.,Sk.,L. E. pyramidaturn West. L. E. bznale (Turp.) Ralfs. Frequent. forma hiam West. C. var. elobaturn Lund. Bo., H., B., C., Bassenthwaite Water. var. RETUSUM var. n. Fig. 8. Var. semicellulis distincte punctatis, inflatione medio granulato, apice late retusa (nee incisa). Long. 27 p; lat. 21 p; lat. isthm. 8 p; crass. 12 p. Kirk Fell. E. dentieulaturn (Kirchn.) Gay. Frequent. Genus Cosrnariunt Corda ; Ralfs. 0.quadraturn Ralfs. H., Hk., Deepdale. C. plicatum Reinsch. Near Blea Tarn. C. sublobatum (BrBb.) Arch. H., Bo., Scarf Gap Pass. C. tatr.ieuiiz Racib. var. novbelandiczcm Nordst. (Freshw, Alg. of New Zeal. and Austr., p. 58, t. 6, f. 6). Long. 46 p; lat. 25 p; Iat. isthm. 14 p; crass. 12 p. Kirk Fell. 724 Transactions of the Xociety. C. Nymannianum Gmn. Hp. C. Hammeri Reinsch. H., Bt., Bo., Deepdale, Bassenthwaite Water, Stye Head Tarn. *C. Clepsydra Nordst. (Desm. Brasil., tab. iii. fig. 29. C. bicardia Reinsch.). Long. 21 p; lat. 21 p; lat. isthm. 4.5 p; crass. 16 p. Fig. 30. Rn. C. COARCTATUM sp. n. Fig. 11. C. parvum, paullo longius quam latius, leviter constrictum, sinu subaperto et obtuso ; semicellulae obtrapezicae, marginibus lateralibus subrectis, apice late truncatte ; a vertice vim ellip- tic= ; a latere visae subcirculares, apice truncate ; membrana levis et subincrassata ad apices. Long. 16 p; lat. ad bas. semicell. 12-12.5 p; lat. ad apic. 13.5-14-4 p; lat, isthm. 7 p; crass. 8 p. Bo. This seems at first sight very similar to C. contructum Kirchn. var. cracoviense Racib. (Nonn. Desm. Polon., p. 28, t. 1, f. lo) but is much smaller and has more truncate ends, a relatively wider isthmus, and a different lateral view. C. Holmiense Lund. var. integrunz Lund. H. Forma cellulis a latere visis pyramidatis et a vertice visis nec late elliDticis. Long. 52 p ; lat. 30 p ; lat. isthm. 16 p ; crass. 17 5 p. Fig. 12. B. C. am;ps Lund. Bn., R. C. granatum BrBb. B., Bo., L., C., Hk.,Esthwaite Water. C. trilobulatum Reinsch. Bn. Long. 23 p; lat. 15.4 p ; lat. isthm. 5 p. C. tetragonum Nag. H. var. Luizdellii Cooke. B. C. variolaturn Lund. Hk.,L. C. obsoleturn (Hantzsch) Reinsch. Bn., Hk. The vertical view was somewhat pointed at each pole just as in Nordst. Alg. et Char. I., tom. xvi. fig. 96, and not as in Keinsch, Algenflora von Mitt. Frank., taf. ix. fig, 5d. C. cymatopleurum Nordst. Bn. " var. tyrolicum Nordst. in Wittr. et Nordst., Desm. et mdog. in Tyrol, p. 30, tab. xii. fig. 5. Hk., not uncom- mon. C. pachydermurn Lund. Bo., H., C. C. perforaturn Lund. Bn. C. pyramidaturn BrBb. Frequent. C. pseudopyramidaturn Lund. Frequent. "C. microsphincturn Nordst. in Wittr. et Nordst., 1.c. p. 33, t. f. 9. Long. 39 p ; lat. 26 p; lat. isthm. 17.5 p ; crass. 18 5 p. Fig. 32. Bo. Alga of the Efiglish Lake District. By WQ~.West. 725 C. nnitidulum De Not. H., Bo., Wythburn, Eirk Fell. C. subtamidurn Nordst. H. C. tunaidurn Lund. L. 0. Phaseolzcs Brkb. H., Scawfell, Scarf Gap Pass, Stye Head Tarn. C. PSEUDATLANTHOIDEUM sp. n. Fig 21. C. parvum, 1&-plo longius quam latius, profunde con- strictum, sinu linear1 ; semicellula subtriangulares, angulis inferioribus latissime rotundatis, lateribus concavis, apice angusto rotundato ; a vertice visa anguste elliptica ; mem- brana glabra. Long. 19.5 p; lat. 13.5 p ; lat. isthm. 4 p; cram 6.5~.L. This differs from C. atZundhoideum Delp. in being relatively narrower and in its different vertical view. C. scenedesmus Delp. B., Bn. C. rectangulare Grun. Bt., Hk. C. bioculaturn BrBb. Sk., B., Hk. *forma devressu Schaar. B. C. tilzctum Ral&. Frequent. "var. intermedium Nordet. Long. 14-15 p; lat. 10-12 p; lat. isthm. 6 p; crass. 8 p; Bo. Frequent. C. exiguum Arch. Hk. * 0. Regnellii Wille (Bidrag ti1 Sydam. Algfl., p. 16, t. i. f. 34). Hk., common. Long. 11-12 p; lat. 11-14 p; lat. isthm. 3.5-4 p; crass. 6 p. Fig. 20. The forms of this varied considerably. Perhaps C. abrupturn Lund. var. gostynieme Racib. (Nonn. Desm. Polon., p. 24, t. ii. f. 13) may be another form of this species. C. SUBCAPITULUM sp. n. Fig. 29. C. parvum, paullo latius quam longius, profunde con- strictum, sinu acutangulo aperto ; semicellula elliptico- angulares ; latera inferiora et superiora recta angulum sub- rectangularem formantia ; apicibus truncatis et subretusis ; a vertice visa ellipticae polis acutis; a latere visa rotundo- elliptica ; membrana laevis. Long. 17 p; lat. 19 p; lat. isthm. 4 p; crass. 7.5 p. Bn. This differs from C. capituZum Roy et Bias. (Jap. Desm. in Journ. Bot., 1886, vol. 25, p. 195, t. 268, f. 9) in the truncate subretuse ends, the acute angles of the semicells, in the non-acuminate sinus, and in the subacute poles of the vertical view. 72 6 Transactions of the Society. C. impessulum Elfv. B., Hk. C. venzlstiim (Brdb.) Arch. L., C., Brandreth, Grisedale Tarn. \-ar. hypohexagonum West. Kirk Fell. f. incrassata West. Sk. C. Hene&irzii ~r&.Very frequent. f. octangularis Wille. Frequent. forma. Fig. 14. Diam. zygosp. sine spin. 22-23 p, c. spin. 33-35 p. Bn. f. Boldtii nob. [C. Meneghinii BrBb. forma h. Boldt (Desmid. fr. Gronland, p. 13, t. i. fig. 15.)] Bt., Elk., common. C. ob2ipuum Norcist. f. major Nordst. Hk. f. minor Nordst. Bn., Langdale. f. minima. Long. 11 p; lat. 9 p;crass. 4 p. Fig. 13. H., Pike of Bliscoe. C. Repzesii Reinsch. B., Esthwaite Water. C. CYMATONOTOPHORUM sp. n. Fig. 23. C. parvum, tam longum quam latum, modice constrictum, sinu aperto cum extremo obtuso ; semicellulae late subrectan- gulares, lateribus subtruncatis subretuaisve, dorso truncato et quadriundulato ; a vertice yisa ellipticae, in utroque latere papilla instructa? ; a latere visa suborbiculares, medio utrobique papilla ornate. Long. 13.5-14.5 p; lat. 13-5-14.5 p; lat. isthm. 5 * 5-6 p ; crass. 9 * 8 p. Hk. This seems a very distinct species ; it has some resemblance in front view on first sight to C. Regnesii Reinsch. (2. substriaturn Nodst. Bn., Stye Head Tarn. *C. subizotabile Rille (Ferskv. Alg. fr. Nov. Sem., p. 36, tab. xii. fig. 16). Trough at Ambleside. C. crenatuna Ralfs. Frequent. C. Nuttallii West. Bt. C: tmiulatum Corda. H. C. mommazum Lund. B. C. tetraophthalmum (Eutz.) BrBb. Frequent. The zygospore was seen from Lake Side. var. Lundellii Wittr. Bo., Bn., R., C., Hk.,Blea Tarn in Borrowdale. C. Brebissonii Menegh. W., Bo., Hp., B., S., C. forma erosa West. W., Hp., Bn., S., L., C., Bt. C. conspersum Ralfs. Bo., B., L., C., Hk. C. Quadrzcm Lund. Long. 73 p; lat. 70 p; lat. isthm. 28 p. Bn., Hk. C. margaritiferum (Turp.) Menegh. H. (at 2400 ft.). B. Scawfell, Crummock Water. AZyg of the English Lake District. By Wrn. West. 727 C. Portianuin Arch. B., Bo., H., R, Bt., Hk.,Blea Tarn, in Borrowdale. C. yeniforme (Ralfs.) Arch. B., Hk., Bassenthwaite Water. *var. cornpressum Nordst. (Freshw. Alg. of New Zeal. and Austr., p. 46, t. 5, f. 5). Long. 48 p; lat. 47 p; lat. isthm. 13 p; crass. 24 p. Hk. C. Logiense Biss. Frequent. C. punctiilatunz BrBb. B., H., Crummock Water, Trough at Ambleside. C. suhpunctulatum Nordst. var. Borgesenii West. Forma semicellulis ad apices leviter convexis, in medio granulis paullo majoribus (7 periphericis et 1 centrali). Long. 33 p; lat. 30 p; lat. isthm. 11 p; crass. 19 p, Fig. 18. C., Hk., Langdale. The centre granules in var. Borgesenii MTest (Contrib. Freshw. Alg. of W. Ireland, plate 21, fig. 9) have been drawn like the others by the artist ; they should have been made larger. (7. Blyttii Wille. Hp., Wythburn. Forma paullo minor. Lat. 10 p; crass. 7 p. H. (at 2400 ft.). C. orthostichum Lund. *var. puiwilum Lund. (Desm. Suec., p. 25, t. ii. f. 10). Long. 25 EL. ; lat. 20 p ; lat. isthm. 5 p ; crass. 12.5 p. Bo., H. C. Botrytis (Bory) Menegh. Very frequent. C. Turpiizii BrBb. var. Luundellii Gutw. Near Cockermouth. C. VEXATUN sp. n. Fig. 33. C. mediocre, paullo longius quam latius, profunde con- strictum, sinu lineari extremo amplia to ; semicellulce sub- trapezicz, lateribus convexis, angulis inferioribus rotundatis et minute undulatis, angulos superiores versus cum undulis majoribus, dorso truncato et levissime subundulato ; a vertice visa oblongo-ellipticce, medio glabro tumida ; a latere visa subcirculares ; membrana grosse granulata, granulis sub- concentrice et subradiatim ordinatis, glabra ad medium ; pyrenoidibus binis. Long. 41-43 p; lat. 36-38 p; lat. isthm. 13-5-14 p; crass. 20-21 p. Ambleside, not uncommon. At first sight this appears like some forms of C. Botrytis (Bory) Menegh., but it is much smaller, it has truncate and almost smooth apices, the lateral undulations are larger towards the apex as in C. Quasillus Lund., and the vertical view has a glabrous irijated centre. It differs from C. Quasillus Lund. and C. subpasillus Boldt in its smaller size and in the smaller central inflation of the vertical view being without undulations, as well as in other particulars. It 728 Transactions of the Society. is quite distinct from C. pramorsum Brhb. (see Nordst. Norges Desm., tab. i. fig. l), and C. formoswlum Hoff. C. prmnorsurn BrBb. B., near Windermere, Crummock Water, Embleton, near Cockermouth, Blea Tarn in Borrowdale. C. Broornei Thwaites. L., Crummock Water. C. ochthodes Nordst. Frequent. Occurs up to 2400 ft. on Helvellyn. var. AM~BUMvar. n. Fig. 31. Var. semicellulis subtruncatis, verrucis depressis irregu- laribus et sinuatis angulis 3-5. Long. 87 p; lat. 60 p; lat. isthm. 21 p; crass. 40 p. Bn., Hk. Frequent. C. confusum Cooke var. regularius Nordst. Hp., Bn. subsp. ambipum West. Hk., Bt. C. amasnum BrBb. H. C. cyliindricum Ralfs. II. C. SUBOYLINDRICUN sp. n. Fig. 22. C. submediocre, diametro l$-plo longius quam latius, leviter constrictum ; semicellulae semi-ellipticae cum lateribus subrectis, irregulariter et dense granulosae, cum annulo granu- lorum majorum ad basem ; a vertice vim circulares. Long. 37 p; lat. 21 p ; lat. isthm. 18 p. L. It differs from C. cyZincZricum Ralfs in the 'semicells not being subquadrate, in being wider towards the base, in the rounded ends, in the granules not being arranged in lines, and in the basal ring of larger granules. C. annulaturn (Nag.) De Bary. vm. eZegans Nodst. Long. 46-52 p; lat. 27-18 p. Hk., Bt., Bo., Pike of ,* Bliscoe. C. subcostatum Nordst. Bo., Esthwtlite Water. C. subproturnidurn Nordst. B. C. Bmkii Wille. H., B., W., near Cockermouth. C. syhalerostichum Nordst. Bo., I]., Sk., Bt., C., Blea Tarn in Borrowdale. C. ccelatum Ralfs. Very frequent. C. ornuturn Ralfs. B., H., W., Hp., near Cockermouth. C. puinarium Lund. B., Bn. C. cyclicurn Lund. Bo., H. var. angulatuna West, Freshw. Alg. of N. Yorks. in Journ. Bot., Oct. 1889, t. 291, f. 2. [C. Nordstedtii Reinsch., Contrib. Alg. et Fung., t. 10, f. 11.1 Lofig. 48 p;lat. 54 p; lat. isthm. 19 p ; crass. 23 p. Fig. 19. Bo. C. speciosum Lund. *var. biforme Nordst. Kirk Fell. A2ga of the English Lake District. By Wm. West. 729 C. subsyeciosum Nordst. H. * C. supaspeciosum Wolle. var. EUARGINATUM var. n. Fig. 24. Var. minor, crenis distincte emarginatis, sinu extremo ampliato. Pyrenoidibus ?inis, Long. 61 p; lat. 52 p; lat. isthm. 18 p. B. C. isthmizm West. L. C. nzonikiforme (Yurp.) Ralfs. R., Crummock Water, Ennerdale. * forma paduriformis Heimerl (Desmidiaceae Alpinae, p. 12, tab. v. f. 11). B. C. contractuna Kirchn. Bn. C. gkobosum Buln. Sk., near Cockermouth. 0.MORSUM sp. n. Fig. 10. C. mediocre, diametro circiter duplo longius, leviter con- strictum, incisura mediana semicirculari ; semicellulae semi- elliptics, angulis inferioribus subacutis ; a vertice visae latissime ellipticie ; a latere viss subcirculares lateribus subcompressis ; membrana laevis. Long. 40.5 p; lat. 23.2 p; lat. isthm. 15.5 p; crass. 20.2 p. Bn. C. connatum Br6b. Bo., C., Hk., Bassenthwaite Water. var. truncatum West. Hk. C. pseudocomaturn Nordst. L. C. viride (Corda) Joshua. Ennerdale. C. psezcdarctoum Nordat. Fig. 16. Hk., W., H., L., Pike of Bliscoe. 6.cucurbita BrBb. Common. Forma major et latior. Long. 42 p ; lat, 27 p. L., Grisedale Tarn, Eirk Fell, Brandreth. 6. palmgulu BrBb. var. De Bwyi Rabh. Hk. 6. obcwzeattm West,. Forma minor latior lateribus leviter concavis. Membrana laevis. Long. 30 p; lizt. 16-17 p ; lat. isthm. 13-14 p. Fig. 8. H., Ba., L., Grisedale Tarn, Pike of Bliscoe. 6. l’hwaitesii Ralfs. H., S. C. turgidurn BrBb. Hk. var. SUBROTUNDUM var. n. Tar. duplo longius quam Iatius ; semicellulis subro- tundis. Long. 140 p; lat. 77 p; lat. isthm. 60 p. Bn. C. Ralfsii Br6b. Sk.,Hk., Brandreth, Grisedale Tarn. C. Cucumis Corda. Very frquent. Occurs up to 2400 ft. on Helvellyn. forma mncjor Nordst. H. (at 2400 ft.). 1892. 3D 730 Transactions of the Xociety. C. De Baryi Arch. B., S., L. C. elegantissimum Lund. forma minor West. Bo., Bn., H., C. Genus Xanthidium Ehrnb. ; Rnlfs. X. armatum BrBb. W., Hk., Kirk Fell. X. acdeatum Ehrnb. B., Bn., C., H. (at 2400 ft.), Deepdale, Black Sail Pass. X. Bre'bissonii Ralfs. R., Deepdale. var. aarians Ralfs. D epdale. X. antilopmm (BrBb.) Kiitz. H., B, S., C., Hk., Bassenthwaite Water. X. cristatum BrBb. Hk. par. uncinatum BrBb. EIlt Genus Arthrodesmus Ehrnb. ; Arch. A. octocornis Ehrnb. Hp., Sk., L. A. Incus (BrBb.) Hass. W., B., R., C., Hp. (cum zygosp.), Ennerdale. Diam. zygosp. s. spin. 20 p; c. spin. 34 p. var. intermedim Wittr. Sk., Elk. A. Ralfsii West. Bn. A. convergens Ehrnb. Bo., R., Hk., Bassenthwaite Water. A. biJdzcs BrBb. var. truncatus West. Bn. A. glaucescens Wittr. forma convexa West. Hk.,W. (cum zygosp). Zygosporae globoss, aculeis simplicibus longis ornata. Diam. zygosp. s. spin. 16.5 p; c. spin. 29 p, Fig. 27. Gen. Staurastrum llleyen ; Ralfs. S. dejecturn BrBb. S., B., Ennerdale. Forma 4-gona. Bo., S., Hk. var. patem Nord. B. S. apiculatuna BrBb. L., Baasenthwaite Water. k7. mucrofiatum Ralfs. W. 8. DicLiei Ealfs. S., R., B., Hk. forma punctata West. Bn. 8. brevispinum BrBb., Bn., Hk. S. cuspidaturn Brkb. R., B., H., Sk. par. .maximum West. B. 8. aristiferum Kalfs. B. X. O'Alearii Arch. S., Sk. 8. megacanthum Lund. W. X. lunatum Ralfs. B., Buttermere. 8. cristatum (Niig.) Arch. Hk., not uncommon. X. avicula BrBb. E. AZgz of the Eihylish Lake Distvict. By Wriz. West. 731 S. furcatum (Ehrnb.) BrBb. S., L. var. armigerum (BrBb.) Kabh. W., C., Hk. "8.senarium (Ehrnb.) Kalfs. Bn. 8. Reinschii Boy. Sk., Hk. 8. hirsutum (Ehrnb.) BrBb. W., B., H., Bt., C., Hk., Blea Tarn in Borrowdale. 8. pilosurn (Nag.) Arch. Bn., C., Bo., Hk., Wythburn, Black Sail Pass. S. Brebissonii Arch. var. BREVISPINUM var. n. Fig. 26. Tar. spinis brerioribus et validioribus. Long. 49 p; lat. s. spin. 42.5 p ; lat. c. spin. 45 p ; lat. isthm. 17.5 p. €3. S. Hystrix Ralfs. B. S. telijierurn Ralfs. Frequent. S. polytriehum (Perty) Rabh. Bn. S. asperum BrBb. C. 8. muticum BrBb. S., Kirk Fell. S. orbiculare (Ehrnb.) Ralfs. Common. forma major. Long 61 p ; lat. 50 p ; lat. isthm. 17 -5 p. Bo. *var. extensum Nordst. A small form. Long. 38-39 p; lat. 25-5-28 p; lat. isthm. 8-10 p. R., Lake Side, Stye Head Tarn. var. depressurn Roy. et Biss. Bn., Hk. S. Bieneanum Rabh. B. S. Hibernicum West. Forms membrana irregulariter punctata. Long. 63 p; lat. 56 p; lat. isth. 19.5 p, L. S. ELLIPTICUM sp. n. Fig. 28. S. mediocre, circiter l$-plo longius quam latius, modice con- strictum, sinu acutangulo et ampliato ; semicellulae ellipticae ; a vertice visa trigonae 1:iteribus leviter convexis, angulis late rotundatis ; membrana lavis ; pyrenoidibiis singulis magnis. Long. 42.546 p ; lat. 29-30 p ; lat. isthm. 13-15 p. Bo. The front view is similar in form to S. turgescens De Not., but the membrane is smooth and the vertical view is different. It differs frcm 8. vesiculaturn Wolle (Freshw. Alg. of U.S., p. 42, pl. liv. f. 6, 7) in its broader sinus and elliptical semicells. S. Kjellmaiti Wille. Sk., E., Bt., Blea Tarn in Borrowdale. S. pygrnzum BrBb. Frequent. 8. turgescens De Not. Trough at Ambleside, Buttermere, Blea Tarn in Borrowdale. S. rnuricatum BrQb. Ho., B., Hp., Kirk Fell. A form of this species occurred at an elevation of 2400 ft. on Helvellyn, which was just as long as broad, and very similar to figs 19 and 20, tab. vi. in Nordst., Dcsmidieer frBn Bornholm. 3D2 732 Transactions of the Society. S. pyramidatum ,West. Bn., 13. S. punctulatum BrQb. Common. Zygospores from Lake Side. S. urnmaurn Hilse. Sk., Scawfell, Easedale. 8. Meriani Reinsch. H., Bt., C., Blea Tarn in Borromdale. 5'. alternuns BrQb. B., S., M'., Bassenthwaite Water. 8. diilatatum Ehrnb. B., Bo., Hk.,H. (at 2400 ft.), Crummock Water. 8. quudrangulare BrBb. Long. 25 p ; lat. s. spin. 25 p, c. spin. 32 p ; lat. isthm. 8 p. L. S. tumidum Bre'b., S., C. S. grande Buln. Bo., Bn. L. S. tricorne (BrQb.) Menegh. Frequent. 8. cyrtocerum BrBb. f. 3-gona. B., W., Deepdale. f. 4-gona. Bn. S. arcuafum Nordst. Brandreth. subsp. SUBAVICULA suhsp. n. Fig. 25. Semicellnla a fronte et a vertice visa ut in 8. avicula, cum processibuv bifurcatis radiantibus sex ad apicem. Long. s. proc. 29 p; lat. 32.5 p; lat. isthm. 9 -5p. Hp. S. ilzJlexun3 BrBb. B. S. polyrnorphum BrBb. W., Hp., Bt., Deepdale, near Ambleside. var. MUNITUK var. n. Fig. 35. Tar. processibus seriebus transversis spinularum mu- nitis ; semicellula a vertice visze triangulares late- ribus rectis. Long. 31 p; lat. c. proc. 36 p. Esthwaite Water, not uncommon. 8. gracile Ralfs. W., Hp., C. var. narzum. Wille. Hp. *var. coronulatzcm Boldt (Siber. Chlor., taf. v. fig. 28). Forma trigona ; corona verrucis emarginatis sex. Long. 21 p ; lat. 32.5 p ; lat. isthm. 6 p. Fig. 36. En. S. paradoxzm Meyen. B., Hp., Crummock Water. S. controvemum BrBb. Hk.,Buttermere. S. uculeatuin (Ehrnb.) Menegh. W., L., Hk. S. vestitum Ralfs. L., Rk.,Deepdale. var. SEMIVESTITUM var. n. Fig. 38. S. minor quam forma typica ; semicellulae apicibus sub- rectis ; a vertice visa triradiata processibus curvatis trifurcatis (ut in 8. cyrtocero), cum spina furcata una ad basem lateris convexi processus uniuscujusque. Long. c. spin. 21-28 p; lat. 34.5-42 p; lat. isthm. 4.5-8 p. L., Rmndreth. s. oe?Jacu?LthumArch. L. S. Xebaldi Reinsch. €hi. Alp?of the English Lake District. By Wm. West. 733

X. PseudosebaZdi Wille var. SIMPLICIUS var. n. Fig. 37. Var. minor, spinis adeatis-nee bifurcatis-dorso, apicibus processuum breviorum longius tricuspidatis. Long. c. spin. 32 p; lat. 46 p.; lat. isthm. 9 p. Brandreth. 8. ezcsteplmnum (Ehrnb.) Ralfs. Bn., L. S. furcigerunt BrBb. B., L. S. sexcostatzim BrBb. B. subsp. PRODUGTUN subsp. n. Fig. 34. S. circiter tam longum quam latum (cum processibus) ; semicelluh processibus brevibus sex (%on lobis), cum apicibus processuum truncatis et sexdentatis, cum annulo granulorum aculeatorum ad basem semi- cellularum ; apices verrucis emarginatis irregulariter dispersis ornati ; a vertice sexradiatis, radiis semi- cellulae utriusque alternantibus. Long. 40-43 p ; lat. 43 p ; lat. isthm. 16-17 p. Bn., B., H. (at 2400 ft.). S. margaritaceurn (Ehrnb.) Menegh. Very frequent. Forma cum annulo punctorum (circiter 14) ad basem semicellularum. Long. 32 p ; lat. 30 p; lat. isthm. 10.5 p. Hp., Grey Knotts. 8. tetracerunt (Kiitz.) Ralfs. W., R., B. Class MULTINUCLEATI. Order SIPHOEEE. Genus Vuuckeria D. C. V. sessilis (Vauch.) D. C. Bn. Class CCENOBIEE. Order VOLVOCINEE. Genus Eudorina Ehrnb. E. elegans Ehrnb. Bn., L. Order PANDORINEI. Genus Pandorina (Bory) Prings. p. mopmn Mull. H., Bn., R., Crummock Water. Genus Gonium (Mull.) Ehrnb. G. pectorale lllU11. B. Genus Chlamydococcus ,4. Br. C, pluvialis A. Br. Deepdale. 734 Tramactions of the Society. Order PEDIASTREB. Genus Pediastrum Meyen. P. angulosuin (Ehrnb.) Menegh. R., Bn., Crummock Water. P. Boryunum (Turp.) Menegh. Frequent. var. granulutum (Kiitz.) A. fir. W., Bn., R., near Cockermouth. P. duplex Meyen (P.pertustcm Kiitz.) B., Bn. P. Tetras (Ehrnb.) Ralfs. Bn. "P. tricormhn Borge (Chloroph. fr%n Norska Finmarken, p. 4, f. 3). R. - P. integrum Nag. Bn., L. Order SORASTREB. Genus S'elenastrzcm Reinsch. "S. acurrzifaatum Lagerh. in Wittr. et Nordst., Alg. exsic., fasc. 9, No. 441 ; Bidrag till kann. om Stocbholms Pecliast., Protococc., och Palmell., p. 71, t. iii. f. 27-30. Bn. S. OBESUIU sp. n. Figs. 50-52. S. cellulis obesis arcuatissimis, apicibus obtusis subacu- tisvc ; familiis e cellulis 4-8 constitutis, facile dissociatis ; apicibus cellularum adultarum 1-52p inter ee distantibus ; contentum cellularum Iste viride, granulatum. Crass. cell. 3-4.2 p ; diarn. max. 6-9 p. Bn. The form of the cells of this species at once distinguishes it from any other, the cells being bent until their ailices almost meet. This sometimes occurred in masses containing from 4 to 24 groups, each consisting of 4-5 calls. Genus Sorastrzim Kutz. 8. spinzdoswn (Kutz.) Nag. Bn., Crummock Water. Genus Staurogenia Kutz. 8.?-ecturzgzLluris (Niig.) A. Br. Kirk Fell, Brandreth. Genus Ccelastruna Nag. C. sphmicurn Nag. Fig. 64. Bn., B., Hk.,L. C. cambricum Arch. Bn., C. C. cztbicum Kag. Bn. C. nzicroporum Nag. R. PROTOPHYTA. Group SCHIZOPHYCEB. Class PROTOCOCCOIDEB. Order EREMOBIEB. C; enus Hormospora Br6b. "11. l,[e~lc(Brdb. (liabh. F1. Eur. Alg., p. 48). Bn. AZga! of the Elzglisli Lake District. By Wm. West. 735 Genus Cylindrocapsa Reinsch. C. CONFERTA sp. D. Figs. 40-42. C. cellulis indivisis quadrato-ellipsoidicis, fere latius quam longius, confertis, cum tegumentis hyalinis circiter binis ciroumvelatis. Lat. cell. 21-26 p; long. cell. 12-20 p; diam. tubul. 24-30 p. Bn. The cells had very firm walls and were filled with intensely green granulose contents. The crowded subangular cells seem to dis- tinguish this from any otlier species hitherto described. Genus Sciadiztm A. Br. S. arbuscula A. Br. Bn., Crummock Water. Genus Ophiocytium Nag. 0. cochbnre (Eich.) A. Br. B., Bn., R., Hk.,Crummock Water. *O. rnajus Nag. Bn. Genus Dictyospharium Nag. D. Ehrenbergianum Nag. En., Angle Tarn, Crummock Water. D. reniforrne Buln. En. Genus Dimorphococcus A. Br. B. Zunatus A. Br. Long. cell. 12-17.5 p; crass. cell. 6.5- 7-5 v. Fig. 39. Bn. Xcenedesnius radiatus Reinsch (Algenff. des Mitt. VOII Frank., p. 81, t. vi. f. vi.) is probably a smaller form of this species, with more rounded apices. Genus TETRACOCCUSgen. n. Cellulae parvEe, globosae vel subglobosae (nonnumquam subangulares), virides, regulariter quaternae et propinqua+ familias parvas irregulares, libere natantes, formantes, cellu- larum 20-80 ; subfamilia singula quaterna tilis delicatis hyalinis subcurvatis sublaxe conjuncta, non-radiatim (forsan reliqus membranarum cellularum seniorurn) ; contenturn chlorophyllosum cellularum cum granulis magnis paucis ; pro- pagatio cellularum divisione planitiei in duas directiones alter- nans, et atque fit cellulis filialibus quattuor in cellula matri- Cali ortis. T. BOTRYOIDES sp. n. Figs. 43-48. Character idem ac generis. Diam. cell. 3.8-5.7 p; diam. famil. 30-57 p. Bn., not unfrequent. The nearest genus to this is Dirnorphococczcs A. Br., but this genus has its quaternate cells of twoform, which character gives rise to the generic name, and the four cells composing these dimorphic groups are somewhat irregularly joined together by short, broad, hyaline processes ; these characters do not apply to Tetracoccus. 736 T!ransactions of the Society. It is also sufficiently distinct from the genera Dictyospha!viuin Nag., Dictyocystis Lagerh., and Botryococcus Eiitz. Genus Apiocystis Nag. A, Bvaziniuna Nag. B., Bn.

Genus Hydrianum Reinsch , TI. heteronaorphzcm Reinsch, W. Sk., Angle Tarn, Genus Characium A. Br. C. Xieboldii A. Br. Near Cockermouth, C. ornithocephalum A. Br. Bn, Genus Dactylococcus hT&gig. "D. infusionum Kag. Gatt. ein. Alg., p. 85, t. iii. Bn. D. De Baryanus Reinsch. Attached to Cyclops, Bowness, Genus Nephrocytiunt Nag, N, NageZii (3run. R. N. LUNATUM sp. n. Fig. 49. N. cellulis lunatis et attenuatis, apicibus snbobtusis, diametro 3-q-plo longioribus, dorm valde convexo, ventre leviter concavo; familiis e celluliclr 4 vel 8 formatis, sub- spiraliter ordinatis ; tegument0 hyalino, diametro duplo longioribus ; contentum cellularum pallidum viride, granu- latum. Long. cell. 14-18 p; lat. cell. 4-6 p; long. tegument. 36-60 p ; lat. teg. 20-32 p. Bn., It. This is a very characteristic species, being abundantly distinct from the other species. Genus Oocptis Nag. 0. Nugelii A. Br. H., near Windermere. 0. solitaria Wittr. Hp., Bk., Hk., L. +C.erama Wittr. Long. cell. 14.5-15.5 p; lat. 10-10.5 p. B. "0.Nova! Semlia? WiUe. forma major Wille. Bo. 0. ELLIPTICA spa n. Fig. 56. 0. cellulis in familias e 4-8 cellulis formuntes consociatis, cellulis oblongo-ellipticis, 24-plo longius quam latius, apicibus rotundatis et non-incrassatis. Long. cell. 24-25 p ; lat. cell. 11-11 *5p. Bt. forma minor. Long. cell. 15-17 p; 1st. 7.5-8 p. Buttermere. This seems distinct from 0, Nova? Semlia! Wille, 0. solitaria Wittr.. &c. Algz of the Elzglish Lake District. By Wm. West. 737 Order PROTOCOCCACEE(includ. PALYELLACEE). Genus PleurococciLs BIenegh. P. ungzdosus B'lenegh. S. Genus Tvoclkxiu Kiitz. T. uciczclifera (Lagerh.) Hansg. Diam. s. spin. 20 p, c. spin. 28 p. Bn. T. UNCINATA sp. n. Fig. 53. T. cellulis parvis globosis, solitariis vel in familiis parvis aggregatis ; membrana cellularum tenui, spinis longis curvatis validissimis ornata ; contentum chlorophyllosum granulosum cellularum l&e viride. Diam. cell. s. spin. 12.5-13.5 p; c. spin. 21-23 p. Bn. Genus Palmella (Lyngb.) Nag. P. mucosa Eiitz. H. P. hyulilza BrBb. H. Genus Botrydilza BrBb. B. vulgaris ErBb. S. Genus Palmodictyon Eu tz. P. viride Kiitz. Crummock Water. Genus Tetraspora Link. T. bullosa (Roth) Ag. Lake Side. Genus Cldorococcum Frieq. C. gigas (Rutz.) Grun. Bn., B., R., Hp. U. REGULARE sp. n. Fig. 55. C. cellulis subrotundatis, singulis, geminatis (rarius ternis), quaternis, vel octonis consociatis ; membrana cellularum sub- crassa ; dispositione chromatophorarum parietali cum puncto rubro unaquaque cellula ; tegument0 hyalino pellucidissimo et non-lamelloso. Diam. cell. s. teg. 12-15.5 p, c. teg. 36-48 p. Hub. amongst Xplmgnum and Utricularia, frequent. Harrop Tarn and Bowness. Also seen from East Cornwall, Devonshire, North and West Ireland. It differs from C. gigas (Eiitz.) Grun. in its very hyaline tegu- ment not being lamellose, in its thicker cell-walls and in the cells being arranged usually in a binate or quaternate manner. Genus Ghocystis Nag. G. umpla (Kutz.) Rabh. H., R., Bn. G. vesiculosa Nag. Frequent, 738 Transuctions of the Society. Genus Sciiizochlainys A. Br. X. gelutinosa A. Br. Diam. cell. 10-12 p. S., Sk., L. S. DELICATULA sp. n. Fig. 57. S. cellulis parvis, globosis subglobosisve, vel singulis vel geminis in familias consociatis ; familiae 1U-50 in matricem hyalinam achroam aggregatz ; membrana tenais dissociata in unam portionem ; divisio cellularum in unam directionem fit. Diam. cell. 5 * 8-6 - 7 p. Bo., Bn., Esthwaite Water. This is a much smaller and more delicate plant than 8.gelutinosa A. Br., the much thinner membrane separating in one piece, the new cell escaping by a lateral slit, and the division of the cells is only in one direction. Genus Eremosyhzru De Bary. E. airidis De Bary. Frequent. Occurs up to 2400 ft. on Helrellyn. Genus Botryococcus Kiitz. B. Braunii Eiitz. B., Bn., Black Sail Pass, near Cockermouth. B. calcarezcs West. Bn. Genus Urococcus Hass. U. insiglzis (Bass.) Kutz. Very frequent. Genus Rhaphidium Eiitz. R. polymorphum Fres. var. falcutum (Corda) Rabh. Very frequent. var. ncicuZure (A. Br.) Rabh. Bn. *R. convolutum (Corda) Rabh. Bo R. biplex Reinsch. Bn. Genus Scenedesrnus Meyen. 8. bijugutzcs (Turp.) Hutz. Near Cockermouth, Bassenthwaite Water. X. alternum Reinsch. Bo., Bn. 8.denticulutzcs Lagerh. var. linearis Hansg. (var. lineatus West). Bn., Hk. S. padricauda (Turp.) BrBb. Frequent. 8.antennatus BrBb. Bn., Rydal Water. S. ucutus Meyen. Frequent. var. obliquus (Turp.) Rabh. Bn., near Cookermouth. var. dimorphus (Kiitz.) Rabh. Bn. Genus Tetraedron Kiitz. T. minimum (A. Br.) Hansg. Lat. cell. 10 p ; crass. 6 /I. Angle Tarn, *T. triyonuni (Nag.) Hansg. Rn. Algtz of the English Lake District. By Vm. West. 739

T, regdare Kiite. (Polyedrium tetraedricum Nag.). Bn. forma PACHYDERMA. Forma membrana crassissima. Lat. 31-85 p; crass. membr. 2-2.5 p. Bn. T.gigas (Wittr.) Hansg. forma OBTUSA. Forma angulis abrupte obtusis. Lat. 27-42 p. Kirk Fell. var. MAMILLATA var. n. Fig. 53. Var. major, angulis mamillatis. Lat. max. 92 p. Bn. T. enorme (Ralfs.) Hansg. R., Rn. Class PHYCOCHROMACEE:. Sub-class Nostochinea. Order NOSTOCAGEBE. Genus Nostoc Vauch. *N.paludosum Kiitz. Bn. N. rnuscorum Ag. .Amongst mosses, Scandals. N. hurnifusuni Carm. R. N. microscopicurn Carm. [N. rupestre Kutz. N. hyalinunz Benn. (N. opccZinum Benn.)]. Bn., R., EL., Bt., Deepdale. Genus Anabtzna Bory. A. sp. Crass. cell. 7.5-8 p; crass. heterocyst. 8.5-9 p. Bn. Order RIVULARIACEB. Genus Dichothrzx Zanardini. D. Orsiniana (Eute.) Bornet et Flah. (Revis. des Nostocac. HBtBrocyst., p. 376). Langdale. Genus Glaeotrichia J. Ag. G. Pisuna (Ag.) Thuret. Pike of Bliscoe. Order SCYTONEMACEE. Genus Microclztzte Thur. *M. diplosiphon Gomont var. CUIVIBRICA var. n. Var. cum articulis prope basem 7.5-8 p crassis, apicem versus 3 p crassis ; vagina exteriore 23-30 p crassa ; hetero- cystis intercalaribus diametro 4-plo longioribus. Crass. vag. inter. 6.5-9 p; long. heterocyst. intercal. 22-24 p, lat. 5 * 5 p. C. No freshwater species of this genus has hitherto been recorded for Britain. The form seen had the trichomes occasionally inter- rupted. 740 Transactions of the Xociety. Genus Xcytonenna Ag. S. COOKEIsp, n. [IS. natans Coolie (Brit. Freshw. Alg., p. 265, pl. 105, fig. 2) non BrQb.]. Crass. fil. 18-24 p ; crass. trich. 6-7 p. Langdale. This species belongs to the section Euscytonema Bornet et Flah. (Revis. des Nostocac. H6t6rocyst., p. 86) ; it has the sheath composed of parallel strata and has distinct dissepiments. S. natans BrBb. does not belong to this genus, it is the same as PZectonema mirabile Thur. (vide Bornet et Flah., 1.c. p. 1131. As Cooke’s description of the specks which he places under X. nntans Brkb. agrees with the Lang- dale plant, I propose to call it 8. Cookei. S.Jiguratum Ag. H., C., Pike of Bliscoe. S. crzcstaceum Ag. [Petroneinafruticulosum Thwaites.] Bo. Genus Tolypothrix Kutz. T. tenuis Kutz. [T.pygmea Kutz. ; T.$accida De Bary.] Bn., H., Hk., Crummock Water. Genus Desmonemn Berk. et Thwaites. D. WmngeZii (Ag.) Bornet et Flah. (Revis. des Nostocac. HBtd- rocyst., p. 127). [CaZothrix DiZlicynii Kutz. ; Desmonema Dillwynii Berk. et Thw.] var. MINOR var. n. Tar. trichomatibus angustioribus. Lat. trich. 5-6 p. Langdale. Exactly similar to the typical form but smaller. Order SIROSIPHONIACELE. Genus Xtigonema Ag. 8. ocellatum (Dillw.) Thur. R. 8. panni,frme (Ag.) Bornet et Flah. Pike of Bliscoe. S, minz&m (Ag.) Hass. Bo. 8. turfaceurn (Eng. Bot.) Cooke. Bt., Langdale. S. marnillosum (Lyngb.) Ag. Langdale. Order OSCILLARIACEB. Genns Oscillaria Bosc. 0. tmerrimcc Kiitz. Near Heswick, near Cockermouth. 0. Zeptotricha Kutz. Bassenthwaite Water, near Cockermouth. 0. sulfusca Vauch. Bn. 0. tenuis Ag. H., Bn., Sk., C. 0. limosa (Roth) Ag. Bo., Vale of Newlands. 0. nigra Vauch. H., Bn. 0. Frolichii Hiitz. Bn. 0.princfp Vanch, Rn., C,, Hk, Alga: of the English Lake District. fly Wm. West. 741 Genus Lyngbya Ag. L. SUBTILE sp. n. Fig. 58. L. solitsria et sparsa, trichomatibus subflexuosis, libere natantibus, distincte articulatis ; vaginis arctis, achrois ; arti- culis diametro duplo ; cytioplasmate pallide aerugineo et homogeneo. Lat. fil. 1.5-1.8 p. Bo., H., Bn., Scarf Gap Pass. This is one of' the smallest species of the genus yet observed. The filaments are frequently interrupted in the sheath and single joints occasionally become separate, as well as parts of the filament. It is sufficiently distinct from L. hyaZina Borzi (Nuova Notariaia, Apr. 1892, p. 40) which occurs in an olive-green stratum and has tortuose and intricate filaments, and its cells longer than broad. L. vulgaris (Kutz.) Kirch. R. (at 2400 ft.). Genus Inactis Kiitz. I, tinctoria (A. Br.) Thur. On Myriophylkm in Crummock Water. Genus Spirulinu Link. 8.oscillarioides Turp. B., Bn. var. iizinzctissima (Hass.) Rabh. Forma anfractibus laxis- simis, 1 in 38 p. Crass. trich. 2 p. Bn. Sub-class Chroococcacez. Order CHROOCOCCACEB. Genus Chroococcus Nag. *C. minor (Kiitz.) Xag. (Gatt. einz. Alg., p. 47, t. i. A, f. 4). H., Bt., S., L., Ennerdale, near Bow Fell. *C. palZidzu Niig. (1.c. p. 46, t. 1 A, f. 2). Sk., C. C. colmrens (BrBb.) Nag. L., Sk., Bn. 0.turgidus (Biitz.) Kag. Frequent. var. VIOLACEUS var n. Tar. cytioplasmate constanter violaceo. Diam. cell. s. teg. 14-18 p; c. teg. 18-22 p. Foot of Bow Fell, near Angle Tarn, along with Aphanothece suxicola Kag. and Ghocupsa quater- mta (BrBb.) Butz. C. GIGANTEUS sp. 11, Figs. 59 and 60. C. cellulis magnis subsemicircularibus, plerumqne binis (rarius quaternis) in familias consociatis ; familiis solitariis ; tegument0 hyalino, leve lamelloso (lamellis 2-3) ; cytioder- mate tenui ; cytioplasmate densissime zruginoso et granulato. Diam. cell. s. teg. 51-58 p ; c. teg. 67-70 p ; crass. teg. 5.4-6 p. Bn., not uncommon. This differs from C. turgidus (Kutz.) Xig. in its very much larger cells with relatively much thinner tegument. 712 Transactions of tke Society.

C. SCHIZODERMATICUBsp. n. Figs. 61-63. c'. cellulis subglobosis vel subtrigonis, nonnunquam sub- reniformibus, binis vel ternis, quaternis in familiis consociatis ; familiis solitariis vel 24aggregatis ; tegument0 crassissirno, stramineo vel fuscescente, valde lamelloso (lamellis 5-1 0), demum irregulariter discedente ; cytiodermate snbcrasso ; cytioplasmate aeruginoso et granulato. Diam. transv. cell. s. teg. 5-8-11 p, c. teg. 21-38 p; diam. long. cell. s. teg. 5-7'6 p, c. teg. 27-42 p. Near Windermere. This is at once distinguished from all other species by the peculiar thick, splitting tegument similar to that of Urococcus insignis (Hass.) Kutz. (Chroococcw mam-ococcus Rabh. et vltr. aureus Rabh.). Genus Ghocapsa Nag. G. atrata Kiitz. 1,angdale. G. caldariorum Rabh, H. G. polydermatica Kutz. Sk.,near Windermere. 0. puaternata (BrBb.) Eiitz. Bow Fell, near Angle Tarn. G. muginosa (Carm.) Hutz. Langdale. 'G. punctata Kag. (Gatt. einz. Alg., t. i. F, f. 6).

Diam. cell. s. teg. 0 9 8-1 p. Langdale. Genus Aphanocapsa Nag. "A. pzclchra (Eutz.) Rabh. (FI. Eur. Alg., ii. p. 49). lliam. cell. 2-5-3 p. Bn. A. GreviZZei (Berk.) Rabh. R., Bn., S. Genus lllicrocystis Kutz. 31. protogenita (Bias.) Rabh. Bn., near Cockermouth, Esthwaite Water. M. marginata (Menegh.) Kirchn. Bn. Genus Clathrocystis Renfrey. C. zrugimsa (Eiitz.) Henfrey. Bn. Genus Ccelosphterium Nag. C, Kzitzingianum Kig. Bn. Genus Merismopedia Meyen. M. glauca (Ehrnb.) Nag. Very frequent. M. sruginea BrBb. Bn. M. irregulare Lagerh. Hp. Genus Xynechococcus Nag. S. zruginosfcs Sag. H., Langdale. *c. crassus Arch. Bn., Kirk Fell. Alg~of the English Lake District. By Wm. West. 743 Genus Glceothece Nag. *G. linearis Nag. (Gatt. eing. Alg., p. 55, t. i. G, f. 2). Hk, L. 'G. violacea Rabh, (Fl. Eur. Alg., ii. p. 61). Diam. cell. s. teg. 0.6-0.9 p, c. teg. 6-9 p. Sk. The teguments were highly refractive. G. cystifera (Hass.) Rabh. var. MAXIMA var. n. Cellula latitudine 1$-plo longior, duplo major quam in forma typica, cytioplasmate granuloso. Long. cell. s. teg. 14-16 p, c. teg. 18-30 p; lat. cell. s. teg. 9-10 p, c. teg. 13-20 p. Bn. Genus Aphanothece Kag. A. microscopica Nag. Bn., R., Scarf Gap Pass. A. saxicola Nag. Bn., Bt., Esthwaite Water, foot of Bow Fell, near Angle Tarn. Genus Glaucocystis Itz. G. Nostochinearum Itz. Bo. Genus Tetrapedia Reinsch. I'.Reinschiana Arch. Bn., Esthwaite Water. Class DIATOMACEZE. Genus Cyclotella Eutz. C. operculata (hg.) Kutz. B. C. Khtzingiana Thw. B., H. (at 2400 ft.). Genus Melosira Ag. M. varians Ag. Bo., Bn., Vale of Newlands, Crummock Water. M. nivalis Sm. Bo., near Windermere. Genus Surirella Turpin. S. linearis Sm. Common. Occurs up to 2400 ft. on Helvellyn. var. constricta (Grun.) Rabh. Hp., Bn., C., Kirk Fell. S. biseriata (Ehrnb.) Bre'b. Frequent. Occurs up to 2400 ft. on Helvellyn. S. angusta Kutz. Bn. 8. spZemdida (Ehrnb.) Kutz. Bn. S. nobilis Sm. H. (at 2400 ft.). S. ovalis BrBh. Deepdale. S. ovata Kutz. Near Cockermouth. 8.minuta BrBb. Bo., near Cockermouth. S. pinnata Sm. Bn., Threlkeld, Blea Tarn in Borrowdale. Genus Cymatopleura Sm. C. Solea (BrBb.) Sm. Bo., Bn., Deepdale, Dubb's 310s~. 744 Tralzsuctions of the Xociety. Genus Epithemiu BrBb. E. turgida (Ehrnb.) Kutz. H., Bn., Crummock Water. E. Westernaanni (Ehrnb.) Kutz. H., C., Pike of Bliscoe. E. I€yndmanii Sm. Bn. E. Xorex Kutz. Bn., B. E. gibba (Ehrnb.) Hutz. Bn., B., L., Bt., Hk. E. ventricosa liutz. Bt., C. E. Zebru (Ehrnb.) Kutz. Bn., B. E. gibberula (Ehrnb.) Kutz. var. rupestris (Sm.) Rabh. (E. rzcpestris Sm.). H., C. E. Argus (Ehmb.) Kutz. Bn., Z., Hk. E. ulpestris Sm. Bn. Genus Eunotiu Ehmb. E. irzcisa Greg. Bn., Kirk Fell, Scawfell. E. diodon Ehrnb. H., Bn., Scawfell. E. triodo?%Ehmb. H., Deepdale. 3. tstraodon Ehrnb. €I., Bn., C., Brandreth. E. Arcus Ehrnb. Bt., Hp., B., Kirk Fell, Easedale. E. mnjus Sm. H., Black Sail Pass. E. bidens Greg. B., C., Hk. E. gracilis Ehrnb. Very frequent. Occurs up to 2400 ft. on Helvellyn. E. pectinuZis Dillw. W., H., B., Bn., C., Wythburn, Crurnmock Water. var. undulatzcnz Ralfs. C., Pike of Bliscoe. Genus Ceratoneis Ehrnb. C. Arcus (Ehrnb.) Kutz. Crummock Water, C. Amphioays Rubh. W., Sk., R., Derwent CVater, Bassen- thwaite Water. Genus Cymbella Ag. C. Ehrenbergii Kutz. Bn., Hk , Bassenthwaite Water. C. cuspidata liutz. Bt., C.,Hk., Buttermere, Threlkeld, Dubb’s Moss. C. furgidu Greg. W., B., Bn., H. (at 2400 ft.). C. gastroides Kutz. B. C. Xmithii Ilabh. (C. Iduetica Sm.). B. C. maculata Kutz. E., Bn., near Cockermouth. C. voit~icosnAg. B. Genus Cocco~~emaXhrnb. C. lunceolntum Ehinb. Frequent. C. cyinbijornze (Iiutz.) Ehrnb. IT., B., Bn., Derwent Water. c. Cktukc Hempr. Very frequent. occurs up to 2400 ft. on Helvellyn. C! parwum Sm. H., B., Threlkeld, Ennerdale, Scawfell, Stye Head Tarn. Algte of the English Lake District. By Wm. West. 745 Genus Encyomma Kiitz. E. empitosum Kiitz. B. E. gracile Rabh. W. Genus AmpAoi*a Ehrnb. A. oiialis Kutz. Bn., W., H., B., H. (at 2400 ft.), Deepdde, Crummock Water. Genus Cocconsis Ehrnb. C. Place.lztula Ehrnb. H., Bn., Derwent Water, near Cockcr- mouth. C. Thwaitesii Sm. B. Genus Achnanthidium Kutz. A. naicrocephalzcm Kutz. Scamfell, Stye Head Tarn. A. ZameoZatum BrBb. B., Threlkeld, Derwent Water, near Cockermouth. Genus Achnanthes Eory. A. exilis Kutz. Very common. Genus Deqaticula Iiii tz. D.tenuis liutz. B. D. obtusa Sm. B. D. sinuata 8m. L. Genus Odontidium Kutz. 0. hiemale (Lyngb.) Kiitz. R., H. (at 2400 ft.), Derwent Water, Crummock Water, Ennerdale, Kirk Fell. 0, mesodon Kutz. Common. Occurs up to 2400 ft on Helvellyn. 0. nizctabile Sm. Frequent. 0. Harrisonii Sm. Bn. Genus Frugilaria (Lyngb.) Ag. F. capucina Desmaz. Bo., H., Threlkeld, Grisedale Tarn, Derwent Water, Vale of Newlands. F. virescens Ralfs. B., Deepdale, Crummock Water. Genus Diatomu D. C. D. vzclgare Bory. B. D. elongatum Ag. B., Grisedale Tarn. Genus Xynedra Ehrnb. S. Zunaris Ehrnb. Common. S. sp. B. This was near to S. longissima Sm., but was straighter and narrower. 1892. 3E 746 Transactions of the Society. S. biceps Kutz. Frequent. 8. pulchella Kiitz. B., H., Kirk Fell, near Cockermouth, Derwent Water. S. UZna Ehrnb. H., Bn, Ambleside, Deepdale, Dubb's MOSS, Bassenthwaite Water. S. spbndens Kutz. Common. S. Acz~s Kutz. B., L., Threlkeld, Esthwaite Water, Stye Head Tarn. S. delicatissima Sm. B. Genus Asteriofiella Hass. A. formosa Hass. Bo., L., H. (at 2400 ft.), Deepdale, Bassen- thwaite Water. Genus Amphipleura Kutz. A. pelliicida Kutz. Bn. Genus hTitzschia Hass. N. Amphioxys (Ehrnb.) Sm. H , Cockermouth. N. comtricta (Eutz.) Pritch. (N. dubia Sm.). 1Zn. N. parvula Sm. Bn., Scawfell. N. sipnoidea (Nitzsch.) Sm. Bn., Derwent Water. N. curvula (Ehrnb.) Sm. Very frequent. N. linearis (Ag.) Sm. H., Bn., B., W., Deepdale, near Coclier- mouth. N. tenuis Sm. B., Bn., Crumrnock Water, near Cockermouth. Genus Nitzschiella Rabh. N. aciczila~is(Rutz.) Eabh. Bn. Genus &Tavicula Bory. N.czcspidata Eutz. B., Ennerdale, Crummock Water, Dubb's Moss. N. rhonzboides Ehrnb. Very frequent. N. serians (BrBb.) Kutz. L., C., Angle Tarn, Scawfell. N. elliptica Kutz. (N. ovalis Sm.). Bo., Bn., L., B., Hk., Deep- dale. N. pygmrea Xutz. (N. minutula Sm.). Bn. N. limosa (Kutz.) Grun. 14. N. amphisbma Bory. Bo., Bn., C., Bassenthwaite Water. N. sphwophora Kutz. Near Cockermouth. N. pusilla Sm. Bo. AT. rhynchoceplmla Kutz. Bo., Bn., near Cockermouth, Bassen- thwaite Water. N. a$inis Ehmb. B., Bn., H. (at 2400 ft.). N. pwna Hutz. Bn., oommon. Seen with auxospores. N. Amphirhynchus Ehrnb. Bn., C., Bassenthwaite Water, Kirk Fell. Algz of the Elzglish Lake District. By Wm. West. 747 A? producta Sm. W., Bn., Vale of Newlands. N. aypendiculata Kutz. B. N. exzlis (Kutz.) Grun. Frequent. N. cryptocephala Iiutz. B., H., Ambleside, Bassenthwaite and Crummock Water. N. clicephula Ehmb. Bn., Derwent Water. Genus Pinnularia Ehrnb. P. nobilis Ehrnb. H. (at 2100 ft.), Deepdale. P. major (Kiitz.) Rabh. Common. Occurs up to 2400 ft. on Helvellyn. P. Rabenhorstii Ralfs. (P. in,terruypta Rabh.). Sk. P. TabeZZaria Ehmb. Derwent Water. P. gibba Ehrnb. Very frequent. P. Zata (BrBb.) Rabh. Bn., H., Bt, C., Brandreth. P. viridis (Ehrnb.) Rabh. Very common. Occurs up to 2400 ft. on Helvellyn. P. alpina Sm. C. P. radiosa (Kutz.) Rabh. Frequent. var. silesiuca (Bleisch) Kabh. Bn. P. boreaZiis Ehrnb. B., Threlkeld. P. acuta Sm. Bn. P. mesolepta Sm. W., Bn., Bt., L., C. P. divergens Sm. H., Bn., Deepdale. P. Brebissonii (Iiutz.) Rabh. Very frequent. var. szLbcapitata Habh. Hp., Bt., B., L., Ennerdale. Genus Frustulia Rabh. l? saxonica Rabh. forma aquatica Rabh. (Navicidcc crassi- nervia RrBb.). Common. Genus Pleurosigma Sm. P. attsnuatzm (Kdtz.) Sm. Threlkeld. P. Spencerii (Quekett) Sm. Bo., near Cockern~outli. Genus Stauroneis Elimb, 8. Plmnicentwon (Nitzsch) Ehrnb. Very frequent. S. gracilis Ehrnb. Bn. S. anceps Ehrnb. B., Bn, Bt., C. S. dilatata Sm. Bn. Genus Schizonema Ag. 8. neglectunz (Thm.) Rabh. Bassenthwaite Water. Genus Goniphonenba Ag. G. teizellunz Kiitz. Frequent. G. diclhoton~umKiitz. W.,H., B., Kirk Fell. G. Vibrio Ehrnb. H., Stye Read Tarn. 3s2 748 Transactions of the Xociety. G. capitatum Ehrnb. Bn., Sk. G. constricturn Ehrnb. Bn., near Cockermouth, Stye Head Tarn, Ennerdale. G. geminaturn Ag. R.,R., B. G. acuminaturn Ehrnb. B., W., H., Bn., Stye Head Tarn, Crummock Water. G. olivaceum (Lyngb.) Eiitz. B., Bassenthmaite Water. G. intricatum Kutz. B., L., C., Stye Head Tarn. Genus Meridi0.n Ag. M. circulare (Grev.) Ag. B., Hp., near Cockermouth. Genus Tabellaria Ehrnb. [r. Jlocculosa (Roth) Kiitz. Very common. var. ventricosa (Kutz.) Rabh. Scawfell, Crummock Water. T. fenestrata (Lyngb.) Kiitz. Common. Genus Tetracyclzcs Ralfs. T. lactcstris Ralfs. B.