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YOUNG AND ARMSTRONG ROBROYSTON FOSSILS, 267
XXIV.—The FOSSILS of the CARBONIFEROUS STRATA of the WEST OF SCOTLAND. By JOHN YOUNG, Vice-President, and JAMES ARMSTRONG, formerly Honorary Secretary.
(Read 13th March, 1873.)
INTRODUCTION. IN the introductory remarks to our General Catalogue of the Carboniferous Fossils of the West of Scotland,* we pointed out the desirability of having lists prepared of the fossils found in each particular group of strata in the various localities where they occur, for the sake of comparison with similar lists from the same geological horizons at other places, stating that " it is only when stratigraphical lists of our fossils are prepared on some such exhaustive plan, that we will ever be able to arrive at anything like a correct notion of the alternate changes of condition under which the flora and fauna of the Carboniferous period existed, as indicated by its beds of terrestrial, fresh water, and marine strata." Our distinguished honorary member, Thomas Davidson, Esq., F.R.S., in a paper recently communicated to the Edinburgh Geological Society, f also urges upon its members the necessity of preparing local catalogues, such as those above indicated, and he points out the immense importance of Palaeontology to Geology, mentioning one or two instances out of numbers which he could adduce, to show where the correct determination of a few fossils has been the means of unravelling the age and position of strata, not only in Britain, but in distant regions of the globe. In making out these catalogues, therefore, we will endeavour, with the assistance of members of the Society, to give from time to time, in the Transactions, a record of the fossils found in the strata of a particular locality, so far as known, and we trust that when these are completed, they will help to show where a species is apparently confined to a particular stratum and locality, or is recurrent throughout a series of beds extending over wide tracts of the earth's surface.
* Trans. Geol. Soc. of Glas., Vol. III., Supplement, 1871. t Trans. Edin. Geol. Soc, Vol. II., p. 184, 1873. 2 D Downloaded from http://trngl.lyellcollection.org/ at University of California-San Diego on January 15, 2016
268 TRANSACTIONS OP THE GEOL. SOC. OP GLASGOW.
It is our intention to give figures and descriptions of several new species contained in our cabinets, as well as to figure some of the rarer forms, and those also of which imperfect representations are given in the works of other palaeontologists.
No. I. ROBROYSTON. Robroyston, the district from which we give the first special catalogue, is historically known as the locality where Sir William Wallace was betrayed into the hands of the English, in August, 1305. It lies about three miles to the north-east of Glasgow, and near the summit of that undulating tract of country which separates the valley of the Clyde on the south from that of the Kelvin on the north. Robroyston may be reached from Glasgow, either by the Garngad and Provan Mill Road, or by train to Bishopbriggs, and thence eastward by the village of Auchenairn. The limestone beds formerly worked there are termed the "Robroyston Limestone Series," but are known by other local names in its various outcrops, both north and south of the Clyde. It is what is termed a "calm" limestone, being of fine, compact texture, and bluish-grey colour when newly broken, but changing into a yellowish-grey on exposure, from the presence of iron. In this district the limestone averages from five to six feet in thickness, and is parted into two beds by a thin layer of shale. It is not very rich in fossils, the organisms being chiefly confined to a few species of Brachiopods and Cephalopods, with an occasional Crinoid stem, etc. But the bed of shale lying immediately over the limestone has yielded a considerable number of species, as will be seen from the list. A few feet under the limestone there is found a bed of coal of varying quality and thickness. It gradually thins along its southern outcrop in this district to a foot or less, while to the north it thickens considerably, and is found in the Kirkintilloch and Campsie districts to be seven and five feet respectively. The limestone at Robroyston was formerly worked in open-cast quarries on the farms of Hillhead, Barmulloch, and at other places in the neighbourhood. From the old shale heaps at these deserted quarries, specimens of the fossils may still be collected, while, by washing and carefully examining the weathered shale, abundance of the smaller organisms may be obtained. Occasionally the limestone and shales are passed through in the pits put down to the Possil upper black-band ironstone worked Downloaded from http://trngl.lyellcollection.org/ at University of California-San Diego on January 15, 2016
YOUNG AND ARMSTRONG—ROBROYSTON FOSSILS. 269
in the neighbourhood, and at these places the fossils characteristic of the strata may be obtained when these pits are being sunk. The Robroyston limestone is overlapped to the eastward by a series of sandstones and shales, stated to be the representatives of the millstone grit, this limestone being made the line of division in the new map of the district prepared by the Geological Survey, between that group and the upper limestone series of this portion of the Lanarkshire coalfield. The equivalent of the Robroyston limestone has long been extensively worked in the neighbouring districts of Garnkirk, Chryston, Bedlay, and Moodiesburn, chiefly as a flux for iron-smelting. It has also been passed through in pits in the parishes of Campsie, Kirkintilloch, and Cumbernauld. On the eastern border of the Lanarkshire coalfield it is found at various places in the Carluke district, having been worked at Gare and Westerhouse in former years. From these places large and interesting collections of the fossils found in the shale have been made, which agree very closely in genera and species with those found at Robroyston. South of the Clyde it is worked in the district around Thornliebank, Pollokshaws, and Barrhead, in open-cast quarries. Its equivalent is also found at Iimekilnburn, south-west of Hamilton, as well as in other districts in and around the borders of our Western coalfield, where, perhaps, it has not yet been so correctly identified, owing to local changes in the composition of the strata, and slight variations in the group of fossils. As formerly stated, the fossils are chiefly contained in the overlying shale, which is of a light grey colour at its junction with the limestone, but gradually changes as it passes upwards into a dark grey shale, in which they are much less abundant. The great majority of the larger species exist in a broken, fragmentary, or crushed condition, as is commonly the case in the soft limestone shales of most localities; still, perfect examples of many of them have been obtained, while all have the original shell-structure very well preserved. None of the comparatively few species found in the limestone are known to be different from those in the shale. It will, how ever, be seen from the list, that the number of species inhabiting this part of the old Carboniferous sea-bottom had very much increased in both genera and species by the time when the over lying shale was deposited. From the greater absence of Corals and Polyzoa in the Robroyston limestone and shales, than in Downloaded from http://trngl.lyellcollection.org/ at University of California-San Diego on January 15, 2016
270 TRANSACTIONS OP THE GEOL. SOC. OF GLASGOW. many of the other Scottish limestone strata, it would seem that the beds were laid down in water of very moderate depth, and that the conditions were not so favourable for the growth and development of these classes as in the formation of some of our other limestones. The structure and composition of the limestone also show that it could not be a very deep-sea deposit, a considerable per centage of clay having been mixed with the lime during deposition, while the comparatively few fossils met with in the stone clearly proves that the stratum was not built up by the growth and decay of organisms, like some of our richly- fossiliferous limestones, it being, like many of our other " calm" or "cement" limestones, formed to a large extent from the chemical precipitation of lime in the sea water—these, likewise, containing very few fossils. The underlying coal-bed indicates that land conditions must have prevailed to a large extent over the Lanarkshire coalfield, prior to the deposition of the limestone; and the intermediate strata, from its fossils, seem to point to fresh or brackish water conditions having obtained during the interval when the coal-bed was being gradually depressed, and the period when the intervening strata were finally covered by the sea. The following sections of a pit sunk to the coal under the Robroyston limestone at Balquarhage, near Campsie, will show the relation of the various strata more clearly than any now to be obtained at Robroyston old quarries. Feet. Inches. Surface soil and boulder clay, 7 0 Dark grey shale, with a few marine shells, 42 0 Light grey shale, with numerous shells, Trilobites, Crinoidea, etc., 3 0 Light grey shale, passing gradually into limestone, with fewer fossils, 1 0 Calm limestone in two beds, parted by layer of grey shale; fossils rather rare, 8 0 Grey calcareous shale, passing upwards into limestone, with very few fossils, 1 0 Bituminous shale, with a few obscure plant remains, ... 2 0 Dark bluish-grey shale; no fossils observed, 2 0 Grey shale, with large round nodules of clay ironstone; no fossils observed, 2 0 Dark grey soft shale; no fossils observed, 1 0 Black semi-bituminous, with small ironstone nodules (doggars); no fossils observed, 1 Downloaded from http://trngl.lyellcollection.org/ at University of California-San Diego on January 15, 2016
YOUNG AND ARMSTRONG—ROBROYSTON FOSSILS. 271
Feet. Inches. Bituminous oil shale, with scales of small ganoid fishes and obscure plant remains, 0 6 Coal inferior in quality at this place; of better quality in pits to the south-east, 5 0 Dark grey sandy shale, with Stigmaria and other coal plants, not passed through, ... 3 0
79 0
NOTE.—Under the above beds in this locality are known to occur a thick group of sandstones and shales, with one or two beds of marine limestone. These have been also passed through in the pits at Robroyston, in sinking to the Possil ironstones. The average thickness of this series of upper carboniferous limestone strata varies from 80 to 100 fathoms, in different portions of the Lanarkshire coalfield. But none of the limestone beds attains a greater thickness than six or eight feet, while many are much thinner. Except in the limestone bands, fossils are very rare throughout the other members of the group; those that have been met with are generally fragmentary remains of plants and fishes, scattered through the sandstones and shales. These are of types that indicate land, fresh, and brackish water conditions, the widely-separated limestones with their overlying shales being the only strata which from their fossils present us with periods when true marine conditions prevailed.
FOR AMINIFER A.
1. ENDOTHYRA RADIATA, Brady. Rare. In the shale.
2. TROOHAMMINA CENTRIFUGA, Brady. Abundant in the shale at Barmulloch and Hillhead. These are the only localities where this species has been found so plentiful, and in such a well-preserved condition.
3. T. INOERTA, D'Orb. Moderately common in the shale.
4. VALVULINA PAL^JOTROCHUS, Ehrenberg. Rare. In the shale.
Note.—We are Indebted to Mr. H. B. Brady, F.L.S., for his kind determination of the species of Foraminifera,
ZOOPHYTA.
1. ALVEOLITES SKPTOSA, Flem. Rare. Limestone and shale.
2. HETEROPHYLLIA MIRABILIS, Dune. Very rare. One or two fragments in the shale. Downloaded from http://trngl.lyellcollection.org/ at University of California-San Diego on January 15, 2016
272 TRANSACTIONS OP THE GEOL. SOC. OP GLASGOW.
3. LlTHOSTROTION JUNCEUM, Fkm. Very rare. In the shale.
4. PALJEACIS (ASTRJEOPORA) OYOLOSTOMA, Phil. Very rare. In the shale on crinoid stems.
5. STENOPORA TTTMIDA, Phil. Very rare. In the shale.
6. ZAPHRENTIS PHILLIPSI, M. Edw. Common. In the shale.
7. Z. SPINULOSA, M. Edw. Very rare. In the shale.
ECHINODERMATA.
1. ARCHJBOCTDARIS URII, Flem. Rare. Fragments of spines, plates, and dental apparatus in the shale.
2. A , Sp. Fragments of small, slender spines, finely striated, and minutely tuber- culated, of apparently an undescribed species, are moderately common in the shale.
3. ACTTNOCRINTJS , Sp. Fragments of stems, and portions of the calices of several species not uncommon in the limestone and shale.
4. PlSOCRINUS GLOBULARIS, DeKoifl. Rare. Portions of the calyx in the shale. [In our General Catalogue, p. 21, the generic name is given as Hydreionocrinus, but we have since been informed by Prof, de Koninck, that it should be Ptiocrinus, as the former name was an error of his printer.]
5. PLATYCRINUS , Sp. Fragments of the stems, and plates of the calyx of several species refer able to this genus, occur in the limestone and shale.
6. POTERIOCRINUS CRASSUS, Miller. Common. Stems and portions of the calyx abundant in the shale; more rare in the limestone.
7. P. , Sp. Fragments of other species not uncommon in the shale.
8. RHODOCRINCS UNIARTICULATUS, De Ron. Very rare. Fragment of the calyx in the shale.
9. R. ,Sp. Fragments referable to other species in the shale. Downloaded from http://trngl.lyellcollection.org/ at University of California-San Diego on January 15, 2016
YOUNG AND ARMSTRONG—ROBROYSTON FOSSILS. 273
ANNELIDA.
1. ORTONIA CARBON ARIA, J. Young. Geol. Mag., Vol. X.,p. 112. Rare. In the shale; attached, or showing where it had been attached to the spines of Productus, etc.
2. SERPTJLA CAPERATTJS, M'Coy. Very rare. In the shale.
3. SERPTJLITES CARBONARIUS, M'Coy. Very rare. In the shale.
4. S. MEM BRAN ACEUS, M'Goy. Very rare. In the shale.
5. VERMILIA MINUTA, Brown. Very rare. On crinoid stems in the shale.
CRUSTACEA.
1. BAIRDIA OURTA, var. PLEBEIA, Jones and Kirkby. Rare. This and the following species of Entomostraca are obtained from the shale.
2. B. STJBMucRONATA, Jones and Kirkby. Rare.
3. BEYRIOHIA BITUBERCULATA, MfGoy. Rare.
4. B. RADIATA, Jones and Kirkby. Rare.
5. CYPRIDINA PHILLIPSIANA, Jones and Kirkby. Very rare.
6. CYTHERE CORNIGERA, Jones and Kirkby. Rare.
7. C OUNEOLA, Jones and Kirkby. Common.
8. C. FABTJLINA, var., Jones and Kirkby. Common.
9. C. VENTRICORNIS, Jones and Kirkby. Rare.
10. KIRKBYA PERMIANA, Jones. Very rare. Downloaded from http://trngl.lyellcollection.org/ at University of California-San Diego on January 15, 2016
274 TRANSACTIONS OF THE GEOL. SOC. OF GLASGOW.
11. K. URII, Jones. Bare.
12. LEPERDITIA OKENI, Mun. Bare.
13. YOUNGIA RECTIDORSALIS, Jones and Kirhby. MS. Common.
14. GIFFITHIDES MESOTUBERCULATUS, M'Coy. Bare. Fragments of this Trilobite occur in the shale.
POL'fZOA.
1. A RCHiEOPORA NEXILIS, De Kon. Bare. In the shale, attached to crinoid stems.
2. CARINELLA CELLULIFERA, i?. Mheridge, jun. Geol. Mag., Vol, X., pi. xv. Moderately common in the shale. Found also at Gare, in the Carluke district. Fragments of this and the following species of Polyzoa are found in the shale. They are, however, neither so abundant nor so well preserved as in the limestone shales of some other localities in the West of Scotland.
3. CERIOPORA INTERPOROSA, Phil. Bare.
4. FENESTELLA MULTIPORATA, M'Coy. Bare.
5. F. OCULATA, M'Coy. Bare.
6. GLAUCONOME BIPINNATA, Phil. Bare.
7. G-. STELLIPORA, Sp. nov., Dr. Young and J. Young. MS. Fragments of one or two other species, apparently undesoribed, in the shale.
8. PAII^EOCORYNE SCOTICUM, Dune, and Jenh. Bather rare. Specimens of the Hydrocaulus in the shale. We place this fossil in this group, and not in Hydrozoa, as we believe it to be Polyzoan processes.
9. POLYPORA VERRUCOSA, (?) M'Coy. Moderately common.
10. RHABDOMESON GKACILE, Phil. sp. Gen. nov., Dr. Young and J. Young. Ann. and Mag. of Nat. Hist., May, 1874, p. 335. Rare. This and the following species were formerly referred to Ceriopora. Downloaded from http://trngl.lyellcollection.org/ at University of California-San Diego on January 15, 2016
YOUNG AND ARMSTRONG—ROBROYSTON FOSSILS. 275
11. R. RHOMBIFERA, Phil Rare.
12. SULOORETEPORA PARALLELA, Phil Rare.
13. SYNOCLABIA BISERIALIS, var. CARBONARIA, R. Etheridge, jun. Geol. Surv. of Scotland. Explanation to Sheet 23, p. 102.
BRACHTOPODA.
1. ATHYRIS AMBIGUA, Sow. Rare. Perfect examples in the limestone, fragments in the shale.
2. CHONETES LAGUESSIANA, De Ron. C. HARDRENSIS, in Gen. Cat. Rare in the limestone, common in the shale, and in good preservation. At this locality this shell does not attain the same large size as those found in the High Blantyre and East Kilbride shales.
Note. —Professor de Koninck is satisfied that this species and C. HARDRENSIS are identical. See Mon. des Fossilles Carbonifires de Bleibei'g en Carinthie, p. 41. Bruxelles, 1873.
3. CRANIA QUADRATA, M'Coy. Very rare. In the shale, on crinoid stems, &c.
4. DlSCINA NITIDA, Phil Rare. In the shale.
5. L. MYTILOIDES, Sow. Rare. In the shale.
6. LINGULA SCOTIOA, Dav. Very rare. A single imperfect example in the shale.
7. ORTHIS MICHELINI, Lev. Rare. In the shale.
8. 0. RESUPINATA, Mart. Common. Found in crushed fragments, and perfect small examples in the shale; rare in the limestone.
9. PRODUCTUS LATISSIMUS, J. de C. Sow. Rare. Limestone and shale.
10. P. LONGISPINUS, SOW. Rare. In the shale.
11. P. SCABRICULUS, Mart. Rare. Perfect examples in limestone and shale. Downloaded from http://trngl.lyellcollection.org/ at University of California-San Diego on January 15, 2016
276 TRANSACTIONS OF THE GEOL. SOC. OF GLASGOW.
12. P. SEMIRETICTJLATTJS, Mart. Moderately common in the limestone; the var. P. Martini, found in perfect and crushed examples in the shale.
13. RHYNCHONELLA PUGNTTS, Mart. Rare. "Well preserved examples of a depressed variety of this shell in the shale.
14. SPIRIPERA LTNEATA, Mart. Rare. In the limestone; perfect examples.
15. S. TRIGONALIS, Mart. Moderately common in the limestone. Perfect small examples of var. S. bisulcatus in the shale.
16. S. URII, Mem. Very rare. A single valve in the shale.
17. SPIREPERINA CRISTATA, var. OCTOPLICATA, Sow. Rare. Crushed fragments in the shale.
18. STREPTORHYNCHUS ORENISTRIA, Phil Rare. Fragments in the limestone and shale.
19. STROPHOMENA ANALOGA, var. DISTORTA, J. de C. Sow. Rare. Portions of detached valves in the shale.
20. TEREBRATTTLA HASTATA, SOW. Rare. Perfect examples in the limestone.
LAMELLIBRANCHIATA.
1. AVICULOPEOTEN ITMBRIATUS, Phil. Very rare. A single valve in ironstone nodule.
2. A. INTEBSTITIALIS, Phil. Very rare. Single valves in shale.
3. A. SIMPLEX, De Kon. Very rare. Single valve in ironstone nodule.
4. AROA LACORDAIRIANA, De Kon. Rare. Perfect and crushed examples in the shale.
5. AXINUS (SCHIZODUS) DELTOIDEUS, Phil. Rare. Casts in the shale.
6. CARDIOMORPHA PUZOZIANA, De Kon. Rare. In the shale.
7. CYPRIOARTHA AOTTTIOARINATA, Armstrong. Rare. Perfect examples in the shale. Downloaded from http://trngl.lyellcollection.org/ at University of California-San Diego on January 15, 2016
YOUNG AND ARMSTRONG—ROBROYSTON FOSSILS. 277
8. C. cREBRICOSTATA, Armstrong. Very rare. A single perfect example in the shale.
9. EDMONDIA GIBBOSA, M'Coy. Bare. Crushed and perfect specimens in the shale.
10. LEDA ATTENUATUM, Flem. Rare. Some specimens attain a larger size than any we have observed from any other locality. Small examples found in the shale agree inform with M'Coy's figures of L. birostrata, and L. leiorkyncha, which are pro bably founded on small and variable examples of L. attenuatum.
11. L. CLAVATA, M'Coy. Rare. In the shale.
12. L. INTERMEDIA, R. Etheridge, jun. Geol. Mag., Vol. X., p. 347, pi. xii., fig. 3. Not common. In the shale.
13. NUCULA GIBBOSA, Flem. Rare. In the shale; crushed and perfect examples.
14. N. LINEATA, Phil. Common. Perfect small examples in the shale.
15. N. Sp. Rare. In the shale.
16. SANGTJTNOLITES IRIDINOIDES, M'Coy. Very rare. A fragment in the shale.
PTEROPODA.
1. CONULA ^ISULOATA, M'Coy. Rare. Fragments, an inch or more in length, occasionally found in the shale; one example only with the aperture in tolerable preservation.
GASTEROPODA.
1. CHITON HUMILIS, Kirkby. A single perfect posterior plate in the shale.
2. CHITON, Sp. Very rare. Fragments of apparently two other species in the shale.
3. DENTALIUM INORNATUM, M'Coy. Very rare. In the shale. Downloaded from http://trngl.lyellcollection.org/ at University of California-San Diego on January 15, 2016
278 TRANSACTIONS OF THE GEOL. SOC. OF GLASGOW.
4. ELBNOHUS SUBULATTJS, M'Coy. Hare. Small specimens agreeing closely with this species, and showing the tooth on the pillar lip found in the shale.
5. EULIMA PHILLIPSIANA, De Kon. Very rare. One or two specimens in the shale.
6. *LOXONEMA OLATHRATULA, Sp. nov. Desc. Elongate, composed of from seven to eight whorls, regularly convex, and separated by a moderately deep suture; surface ornamented with fine, close, spiral ridges, intersected by slightly arched costm, also fine, but very distinct, both sets covering the entire whorls from base to apex; aperture slightly imperfect in our specimens, but it appears to be the same as in the other Loxonema. Length, two lines; diameter of body-whorl, two-thirds line. Obs. The prominent convexity of the whorls, together with the sharp intersecting costulae, distinguish this beautiful little shell from the other species of the genus. It occurs also at Orchard, near Pollokshaws, in shale. At Robroyston it is rare, and is found usually among the shale washings.
7. L. CURVILINEA, Phil. Common. Perfect examples in the shale. This shell appears to be rare in most other localities.
8. L. SOALAROIDEA, Phil. Common. Perfect examples in the shale.
9. MAOROOHEILUS AOTTTUS, SOW. Common. Perfect small specimens in the shale.
10. M. FTJSIFORMIS, SOW. Rare. Small specimens in the shale.
11. M. MIOHOTIANTJS, De Kon. Rare. One or two perfect in the shale
12. M. SEMISTRIATUS, Sp. nov. Desc. Acutely conical; spire composed of from five to six moderately- rounded whorls; body-whorl, two-thirds the length of the shell, smooth; other whorls distinctly marked with numerous close-set and slightly-arched transverse stria; mouth imperfect, apparently the same as in other species of the genus. Length, four lines; width of body-whorl, two and a half lines. Obs. This little shell approaches closely in form to that of M. acutus, found in the same bed, but is at once distinguished from that species by its distinctly striated spire, and smooth body-whorl. Young specimens have the whole shell striated. Rare. In the shale. Found also in the shale at Orchard.
* Figures of this and other new and rare species will be given on Plate I., to accompany our next paper, which will be on the Fossils of the Orchard Cement limestone. Downloaded from http://trngl.lyellcollection.org/ at University of California-San Diego on January 15, 2016
YOUNG AND ARMSTRONG—ROBROYSTON FOSSILS. 279
13. MURCHISONIA FIMBRICARINATA, Sp. nov. Desc. Elongate, conical; spire of eight slightly-angular and gradually- increasing whorls; suture moderately deep; surface marked with three spiral grooves, between which there are two fimbriated, or ribbed bands, the upper or that nearest the apex of the shell being broadest, most distinctly marked, and placed nearly on the centre of the whoi'ls. Mouth imperfect. Length, three and a half lines; width of last whorl, one and a half lines. Obs. This species is distinguished from others of the genus by the fimbriated ornamentation of its spiral bands. Bare. One example in the shale.
14. M. STRIATULA, De Kon. Bare. A few examples only found in the shale.
15. NATIOOPSIS BOBROYSTONENSJS, Sp. nov. Desc. Subglobose; spire composed of four to five convex whorls, with a blunt termination, the last occupying fully two-thirds of the total length of the shell, bulging considerably, and bending round gradually towards the columella without losing its fulness; suture vei*y distinct and slightly channelled between the outer and penultimate volution; aperture, long- oval; columella bent inwards and flattened; surface covered with promi nent, close, semi-arcuated costulxn. Height, one and a half lines; width of body-whorl, two lines. Obs. This beautiful little Naticopsis occurs at South Hill, Campsie, in a bed of shale overlying the Hosie limestone (lower limestone series), along with Goniatites, Nucula, Spirifera Urii, etc., and in the upper limestone series at Orchard. At these localities it is very rare, and it is only at Bobroyston that it is found in considerable numbers. Professor de Koninck, to whom we submitted specimens, considered this shell to be quite distinct from any other Naticopsis within his extensive experience, and we have his authority for describing it as a new species.
16. PLEUROTOMARIA BENEDIANA, De Kon. Bare. A few examples in the shale.
17. P. CARINATA, SOW. Yery rare. A single crushed example in the shale.
18. P. OONTRARIA, De Km. Bare. Small specimens in the shale.
19. P. FRENOYANA, De Kon. Bare. One or two tolerably perfect specimens in the shale.
20. P. MON1LIFERA, Phil. Common. Perfect specimens in the shale.
21. P. STRIATA, SOW. Very rare. One or two in the shale. Downloaded from http://trngl.lyellcollection.org/ at University of California-San Diego on January 15, 2016
280 TRANSACTIONS OF THE GEOL. SOC OF GLASGOW.
22. PLATYOERAS VETUSTUS, Sow. Bare. Small examples in the shale.
23. BELLEROPHON DECUSSATDS, Flem. Bare. In the shale.
24. B. DUOHASTELLI, Lev. Bare. One or two specimens in the shale.
25. B. LEVETLLEANUS, De Kon. Bare. In the shale.
26. B. URII, Flem. Common. Small and full grown; perfect specimens in the shale; casts in the limestone.
CEPHALOPODA.
1. ACTINOCERAS GIGANTEUM, Sow. Bare. Specimens several inches in length in the limestone; crushed fragments of the shell in the shale.
2. CYRTOOERAS GESNERI, Martin, Very rare. One or two fragments in the shale.
3. C. UNGUIS, Phil. Bare. Fragments in the shale.
4. GONIATITES EXOAVATUS, Phil. Bare. In the shale.
6. G. IMPLICATUS, Phil. Very rare. Single specimen, imperfeot, in the shale.
6. G. MUTABILIS, Phil. Bare. In the shale.
7. G. PAUCTLOBUS, Phil. Very rare. One or two examples from the shale.
8. G. STRIOLATUS, Phil. Very rare. One example in ironstone nodule in the shale.
9. G. VESICA, Phil. Very rare. One or two examples from the shale.
10. NAUTILUS INGENS, Mart. Very rare. Casts in the limestone; fragments in the shale.
11. N. NODUEROUS, Armstrong. Bare. Fragments in the shale. Downloaded from http://trngl.lyellcollection.org/ at University of California-San Diego on January 15, 2016
YOUNG AND ARMSTRONG—ROBROYSTON FOSSILS. 281
12. N. QUADRATUS, Flem-. Bare. Fragments in the shale.
13. ORTHOCERAS ATTENUATUM, Flem. Common. Well-preserved fragments in the shale.
14. 0. SUBCENTRALE, De Kon. Bare. Fragments in the shale.
15. 0. UNDATUM, Flem. Common. Well-preserved fragments in the shale.
PISCES.
1. PETRODUS PATELLIFORMIS, M'Coy. One example only found in the shale.
2. BHIZODOPSIS GRANULATUS, Ag. Bare. Found in ironstone; nodules in the shale.
Note.—The species in the foregoing list are contained in our own cabinets, and in those of Mr. James Thomson, F.G.S., Mr. vid Robertson, F.G.S., and Mr. James Neilson.