Yol. 5 i.] rxsMI~,r r~rsr~wATra T.As~rr~raA~cr~,zA. .337

25. 21 CO~PAI~lS0N Of the FRI~SHWAT~'RLAI~ELLII3RAlqeHIATA from Russ1& with those from the KxRoo SYSTEM of SOUTr~ AfricA. By Dr. WLADIm~ AMALITSXY, Professor of Geology and Pal~eon- tology in the University of Warsaw. (Communicated by Dr. HaNsr WoovwArr, F.R.S., P.G.S. Read April 3rd, 1895.)

[PLATESXII. & XIII.]

I~TRO~VCTIO~r SoME palseontologists, such as Owen 1 (1876), Twelvetrees 2 (1880)., Trautschold 3 (1~84), and others, have pointed out the resemblance which exists between the reptilian fauna of Perm, in" Russia, and that of the Karoo formation of South Africa. This similarity was based on the fact that the reptiles of Perm described as /~ho- palodon, Fisch., Brithopus, Kut., OrthoT~, Kut., Deuterosaurus, Eichw., Cliorhizodon, Tul., Oudenodon, Traut., and ethers were referred to the Theriodontia, a group represented in the Karoo Series of South Africa. The Russian Permian reptiles referred to have been recently studied by Seeley,4 who has come to the conclusion that they are closely allied to the South A[rican types, but cannot be placed in the same subordinate groups. This author considers them as a new group, Deuterosauria, exhibiting a strong affinity with both the Placodontia and Theriodontia. In 1892,~ when describing the lamellibranchiate fauna from the Oka-Volga basin, I pointed out that the typical shells called Pala~o- mutela from these deposits were also known from the Karoo Series of South and Central Africa, and had been described as Iridina by Daniel Sharpe ~ and Profi T. Rupert 5ones.: At that time, not being in possession of the original forms from the Karoo Series, I, of course, could answer only for the identity of the genus, though, judging from the description given by Daniel Sharpe and Rupert Jones, it was easy to observe that they possessed characters cor- responding to those which I referred to the group of Palveomutela I, wstranzewi. I then expressed the opinion that, in consequence of so wide a distribution of Palceomutela, the species of this genus, Owen, 1~., ' On :Evidences of Theriodonts in Permian Deposits elsewhere than in South Africa,' Quart. Journ. Geol. Soc. vol. xxxii, p. 352. ') Twelvetrees, W. ]t., ' On Theriodont Humeri from Upper Permian in Orenburg,' Bull. Soc. Imp. Nat. Moscou, vol. lv. pt. i. p. 123. 3 Trautschold, 'Die Reste permischer Reptilien des pal~eontol. Cabinets d. Univ. Kasan,' Nouv. M~m. Soc. Imp. Nat. Moscou, vol. xv. (1884). 4 Seeley, H. G., ' Further Evidences of the Skeleton in Deuterosaur~sand Rhopalodon from the Permian rocks of Russia,' Phil. Trans. Roy. Soc. vol. clxxxv. (1894) p. 663. 5 , Ueber die Anthracosien der Permformation l~usslands,' Pa]seontographica, vol. xxxix, p. 209. 6 Sharpe, D., Trans. Geol. Soc. ser. ii. vol. vii. (1852) p. 226. 7 Jones, T. R., Geol. Mag. 1890, pp. 410 and 557. 2r2 338 1,aoF. w. A~AT.r~KY O~t P~RMIA~t [Aug. x895,

after a closer study of the lamellibranchiata from the Karoo formation, might perhaps prove to be of value for instituting a parallel between the hornet,axial deposits of the Russian Permian and the Karoo system of South Africa. My recent studies of some lamellibranchiata from the Beaufort Beds of the Karoo system of South Africa, kindly placed at my disposal by the staff of the British Museum of Natural :History (David Fraser collection from Bedford, and fossils from the shales at Kimberley), and of those in the Museum of the Geological Society of London (Bain and Rubidge collection from Graaf Reinet), enable me to state that they are extremely like those from the :Permian freshwater deposits of I~ussia. From the Karoo system (Beaufort Beds of Graaf Reinet) of South Africa, the following lamellibranchiata were described by Daniel Sharpe : l Iridina (?) rhomboidalis, Iridina (?) ovata, Iridiaa, sp., and Cyrena, sp. Prof. T. Rupert Jones '~ has described Uyrena (?) neglects from the village of Balfour on the right bank of the Kat River, north of Graaf Reinet. After the study of the above- mentioned pal~eontological material I have defined the following forms :~ I. Group of Pal~omutela Inostranzewi. l. Pa~omutela rho mboidalig, Sharpe (Beaufort Beds, Graaf Reinet). 2. Palceomutela ovata, Sharpe (ibid.).

II. Group of Paheomutelr Keyserlingi. ~}. Palceomutela, eL Keyserlin.qi, mihi (ibid.). 4. Pal~omutela, n. sp., aft. orthodonta, mihi (Shales at Kimberley Diamond Mines). 5. Palceomutela trigonalis, mihi (ibid.). 6. Palveomutela, n. sp., aft. Golowkin~kiana, mihi (ibid.).

III. Group of Pal~omutela Verneuili. 7. Paleeomutela semilunulata, mihi (Beaufort Beds, Graaf Reinet).

IV. Group of Pakeomutela Murchisoni. 8. Palovomutela Murchisoni, mihi (Beaufort Beds, Bedford). 9. Paleeomutela plans, mihi (Beaufort Beds, Graaf Reinet).

V. Group of Pal~anodonta Fischeri. 10. Pal~anodonta subcastor, mihi (ibid.). 11. Palo~anodonta okengis, mihi (ibid.). All these groups and the following speeies--Pala~omutela Ke.y- serlingi, P. trigonali~, P. 8emilunulata, P. Murchisoni, P. 21ana, Trans. Geol. See. set. 2, vol. vii. (1852) p. 226. Geol. b[ag. 1890, p. 410. ~rOl' 5 I.] I~RESHWATERLAMELLIBRANCHIATA~ 339

P. subcaztor, and P. okensis--are known in Russia from the upper horizons (A, B, C) of the Permian marls and sandstones of th~ Oka-Volga basin, l These upper horizons, according to the facts ex- plained in my above-quoted paper, 2 I determine as the freshwater equivalent of the German Zechstein. Consequently, the Beaufort Beds of the Karoo Series, if considered as a hom5taxial equivalent of those deposits, ought to be regarded as Upper Permian. But it is necessary to remark here that, with regard to the age of these rocks, Russian geologists cannot come to any fixed conclusion. The majority refer them to the Upper Permian, and only a few regard them as passage-beds between Permian and Trias. From what ]: have said above it is evident that the lamellibranchiata of the Upper Permian marls and sandstones of Russia resemble those from the Beaufort Beds of South and Central Africa. The Permian freshwater lamellibranchiata of Russia, which bear traces of genetic relationship with the Anthracosid~e, and were already well represented in Permo-Carboniferous and Lower Permian times, are undoubtedly much older than the African fauna of the Beaufort Beds; this, we may conclude, emigrated from Russia. It is probable that the Gondw~na Beds of India have been the con- necting-link between these deposits. But even if we admit, during the Permian epoch, the existence of an uninterrupted Russian- Indo-African Continent, the similarity of the freshwater fauna of such distant localities as Eastern Russia and South and Central Africa will still remain one of the most interesting problems of geology. The flora and even the rich vertebrate fauna from these Russian Upper Permian deposits, which I consider as homotaxial and synchronous with the Beaufort Beds of the Karoo Series, have not yet been described. The numerous remains of reptiles found in these deposits will probably prove, after a close study, to have a greater resemblance to the African Theriodontia than the new group of Deuterosauria, created by Prof. ]5. G. Seeley, which includes forms from the lower horizons of the Russian Permian formation.

DESCRIPTION OF FOSSILS. During my residence in London I have been enabled to study the following collections from the Karoo Series of South and Central Africa :-- 1. Those in the Museum of the Geological Society of London, made by Mr. Bain and Dr. Rubidge, some of which specimens required development before I could ascertain their characters. A. Lo~alitie$. South Africa, Karoo Desert and its vicinity, and Graaf Reinet. A reddish-brown sandstone with fossils, amongst which the following are described by Daniel Sharpe : Zridina (?) rhomboidalis, 1 Last year Netshayeff found some species of the above-mentioned groups iu marls and sandstones of Eastern Russia, but I regret that I am unable to agree with most of his definitions, Trans. Nat. I-list. $oc. Kasan, vol. x~vii. (1894) p. 4, 2 Pal~eontographica, voL xxxix, p. 210. 340 PRo1,. w. AxAr.ITsxZ O~ I'ZZMIA~ [Aug. ~895,

Xridina (?) ovata, Irldina (?), sp., Iridina (?), sp., ~frena (?). This sandstone, which consists of casts of lamellibranchs, resembles iu external appearance and other characters the rock developed near Nishny-Novgorod in the upper horizon (B) of Permian marls and sandstones. Among these shells it was easy to recognize forms of the group Pal~eomutela Inostranzewi, but I am unable to give a more definite description, as I had to deal with casts only, though one impression, showing the irregularly striated hinge-margin so very typical of Palceomutela, was well preserved. I was very glad to find the original from which Sharpe made his drawing of the multi- dentate hinge of Iridina (?). These teeth are small and very irregular, though on Sharpo's drawing they appear quite regular. There are a great many small casts, undoubtedly identical with Russian forms from the same deposits, but unfortunately in a bad state of preservation. Some of these small casts belong to the groups : Paleeomutela Keyserlingi (very like the species P. ovalis, m.) and Palceomutela Murchisoni (very like the species P. lcevis). B. Locality marked. South Africa : Karoo Desert. Some pieces of a dark calcareous shale containing shells with external sculpture and hinge-margins preserved. From this shale I cleared off some shells, which proved to be Pal~anodonta (Naiadites) aubca.stor, mihi, and Palceomutela semilunulata, mihi. The first is found on the Russian horizons B and C, and the second on the horizons C and D of Permian marls and sandstones near Nishny- Novgorod. C. Locality marked. Karoo Series: Graaf Reinet. The same calcareous shale containing Palceanodonta (Naiadites) olcensis, mihi, and Palceomutela, cf. Keyserlingi, mihi, both of which forms are found on the horizons B and C of the Upper Permian marls and sandstones near Nishny-Novgorod. D. Locality. Bloemkop, near Graaf Reinet. Collector, Dr. Ru- bidge, 1857. The rock similar to that before mentioned. On the label is written the following: Unio (?) with PhyUotheea (?), Tylo- pter/s. This Un/o I determine as Palceanodonta (IVaiadite#) okensis, mihi. E. Locality. At the village of Beaufort on the right bank of the :Kat River. Collected by Mr. A. G. Bain. Two pieces of greenish- grey calcareous shale with many small lamellibranchiata, some of them being described by Prof. T. Rupert Jones (Geol. Mag. 1890, p. 410)as Cyrena (?)neglecta. Perhaps some of these shells can be referred to the group of t'al~omutela Keyserlingi, and especially to the species subovalis. 2. Through the kindness of Prof. T. Rupert Jones I have been able to examine six small lamellibranch-casts belonging to the :Mineral Department of the British :Museum (Natural History) numbered 66550, having a label which runs as follows :--' Karoo Shales, Diamond Mines, Kimberley, South Africa.' Prof. T. Ruper~ Jones informed me that these shales belong to the lowest horizon of the Karoo Beds at Kimberley. It was easy to recognize among these forms, especially those with a well-preserved external u 5 ~.] FRES~WATEaLAMELLIBRANCIIIATA. 341 sculpturing, that they belong go the group of Palo~omutela Keyser- lingi and to the species: P., n. sp. aft. orthodonta, mihi, P. trigo- nalis, mihi, P., n. sp. aft. Golowl~'~nskiana. This group is found on the horizons, A, B, C, of the Upper Permian marls and sandstones of the Oka-Volga basin. 3. Prof. T. Rupert Jones has shown me a piece of greenish-grey shale containing numerous shells described by him as Iridina (?) oblongs ~ which was brought by Prof. Henry Drummond from Maramura near Lake Nyassa, Central Africa, and is now in the British Museum (Natural History). Prof. Rupert Jones considers these fossils similar to It{dins(?) described by Sharpe from Graaf Reinet in South Africa. They are badly preserved, exhibiting only internal casts, thus preventing a more definite determination, but probably we have here" also tbrms representing the groups Pahro- mutela [~wstranzewi and Palceanodonta (2Vaiaditea) Fiacher~, found on the upper horizons of the Permian marls and sandstones of the Oka-Volga basin. 4. Mr. R. Bullon Newton has been kind enough to show me the David Fraser Collection preserved in the Geological Department of the British Museum of Natural History. Among numerous lamellibran- chiata from the Karoo Series (Beaufort Beds) I was enabled to determine a well-preserved specimen as Palceomutela Murchisoni, mihi var. (loc. Bedtbrd, South Africa), so very characteristic of the upper horizons of the Permian marls and sandstones ncar ~lishny- l~ovgorod and Gorbatoff. From the foregoing remarks it will be seen tha~ those forms which could be defined are from the Beaufort Beds---partly from the upper (Graaf Reinet, Bedford) and partly from the lower (Kimberley) horizons ; and they belong to the genera Palveomutela, mihi, and Palceanodoma, mihi, which I consider referable to the family Anthracosidm.

ANTHaAC0Sln~ (PAT.~0UNIoNIna0, mihi. .Palceomutela, mihi. 1852. Irldlna (?), Sharpe, Trans. Geol. Soc. ser. 2, vol. vii. p. 2'26. 1886. Anthraeosia, Amalitsky (pars), 'Ueber das Alter d. Stufe d. Bunten Mergeln im Bassin d. Oka und Volga.' 1889. Anthracosia, Krotow (pars), M6m. Com. G6ol. de la Russie, vol. vi. pp. 4@1, 511. 1890. Iridir~a (?), T. Rupert Jones, Geol. Mug. 1890, pp. 409, 553-558. 1892..Palceomutela, kmalitsky, Pakeontographica, vol. xxxix, pp. 159-160. Generic diagnosis. Shell equivalve, inequilateral, elongated, rhomboidal, trapezoidal, ovate, triangular. Ligament external. Hinge-margin curved, angulated, or straight, thickened below and behind umbones, covered with numerous irregular, transverse or oblique, small striee situated on both sides of the umbo, or more rarely behind the umbo only. Muscular scars 6; adductors and pedal (retractor) muscles strong, sometimes transversely jagged or

1 Geol. Mag. 1890, p. 557. 342 1,ao1,. w. ~tALI~X~" o~ l, zmlIA~ [Aug. x895; wrinkled; the anterior and posterior adductors are oval and large, the former being excavated posteriorly, and each surmounted by small pedal muscular scars, the anterior one of which is separated and situated under the hinge-line; behind the anterior adductor- scar is a supplementary small lunulate scar and a corresponding muscular impression in the cavity of the umbo. Pallial scar entire. Horizon. Freshwater deposits of the Permian system of Russia and of the Karoo Series of South Africa. The genus Pa~omutda presents a very natural group, the numerous species of which are closely bound ~ogether by inter- mediate forms, notwithstanding which it has been possible to distinguish four groups among the Russian forms: 1, group of P. Verneuili ; 2, group of P. Keyserlingi ;3, group of P. Inost,'an- zewi; and 4, group of P. Murchisoni. Aft these four groups are also found in the Karoo Series of South Africa. Their general characteristics are as follows :~ 1. Group of Pa~omutela Verneuili. Shell comparatively large, transverse, elongate, oval, as a general rule flattened, with tumid and slightly prominent umbones. 2. Group of Pah~omutela Inostranzewi. Shell as a general rule smaller than that just mentioned, elongate, rhomboidal, rectangular, triangular, oval, very convex, with prominent umbones; a strong ridge extends from the umbones diagonally across the shell to the posterior inferior angle; swollen in the direction from the umbones backward towards the inferior angle, and compressed in the posterior part. 3. Group of Paleeomutela Keyserlingi. Small shell, great variety of shapes: elongate, rectangular, oval, trigonal, convex, with moderately prominent umbones ; very tumid ridge, extending from the umbones backwards to the inferior angle. 4. Group of Palveomutela Murchisoni. Shell rhomboida], of various dimensions, with very prominent umbones ; ridge strong, sometimes sharp, concave posteriorly, extending from the umbones diagonally across the shell to the posterior inferior angle ; anterior part swollen, posterior flattened.

Forms of the Group Pal~omutela Inostranzewi. PAI~O]~UTELA RHOMBOIDALIS,Sharpe (aft. P. Inostranzewi). (P1. XII. figs. 1 and 2.) Compare Irldina (?) rhomboidalis, Sharpe, Trans. Geol. Soc.ser. 2, vol. vii. (1852) p. 225, pl. xxviii, fig. 2. 1892. Pal~omutela Inostranzewi, Amalitsky, Pal~ntographica, vol. xxxix, pp. 172, 173, pl. xx. figs. 21, 22, 24-28. A broken piece of an interior cast (Bain Collection) with impres- sion of the transversely striated hinge-margin, which is not quite rightly reproduced by Sharpe (op. cir. fig. 2), belongs undoubtedly to the group of -Pa~omutela Inostranzewi, and is quite identical with the numerous casts of this group found at Nishny-Novgorod in the reddish-brown sandstone of horizon B, I have not figured these Vol. 5 I.] FRESHWATERLAMELLIBRANCHIATA~ 343 casts in my monograph, because I had in my possession shells in a better state of preservation. Lethality. South Africa : Graaf Reinet.

PAL2EO~UTELA OV~-TA, Sharpe. 1852. ~ridina (?) ovata, Sharpe, Trans. Geol. Soc. ser. 2, vol. vii. p. 22% pl. xxviii, figs. 3 and 4. These fossils, and especially that represented by fig. 4 (in Trans. Geol. See.), belong without doubt to the group of Palceomutela Inostranzewi ; I came to that conclusion during my recent study of the original specimen, and I am constrained to remark that the drawings given by Sharpe are too much restored and therefore far from being accurate. I find also that the specimen which served as an original for Sharpe's description of the hinge-margin of Iridina ovata belongs perhaps to another species (Pl. XII. fig. 3). Locality. South Africa : Graaf Reinet.

Forms of the Group Pal~eomutela Keyserlingi. PA]5~O~IUI~SLA, n. sp., aft. OttTltODONTA, mihi. (P1. XII. fig. 5.) Compare 1892. Palveomutelaorthodonta, Amalitsky,Pal~eontographica, vol. xxxix. p. 169, pl. xxi. figs. 18-23, 27, 28. The South African representative of this species differs from the Russian forms by having somewhat more prominent umbones and more anteriorly curved beaks. Although the one specimen examined proves to be closely related to P. orthodonta, it is necessary, for the want of further material, to consider it provisionally as a new species. Dimensions~: length 12, breadth 8, depth 6; average size of Russian forms : length 11~, breadth 7, depth 5. :In Russia Palveomutela orthodonta is found in the Permian marls and sandstones of the Oka-Volga basin at horizons A, ]3, C, and is especially characteristic of horizon C. Locality. South Africa: Diamond mines at Kimberley. laAL~O~UTELA TRIGONALIS, mlhi. (P1. XII. fig. 6.) 1892. Pa~omutela tri#onalis, Amalitsky, Palmontographiea,vol. xxxix, p. 170, pl. xxi. figs. 15-17. This shell differs from the Russian type, possessing somewhat more prominent and more anteriorly curved umbones. Such variations are frequent in the Russian examples of this species. Dimensions : length 13, breadth 9, depth 6. Russian forms are very variable in size, the medium being: length 13, breadth 8, depth 7. In Russia Pa~omuteZa trigonalis is found on the upper horizons A, B, and C of the Permian marls and sandstones of the Oka-Vatga basin. Locality. South Africa : Diamond mines at Kimberley. 1 All measurements are in millimetres. 344 vRov. w. AtrALITSKY ON PERMIAN [Aug. 1895 ,

PAr.~0~rTELA aft. GOLOWXINS,rt~A, mihi. (Pt. XII. fig. 7.) Compare 1802. Paheor~utela G-olowkinskiana, Amalitsky, Pal~eontogTaphiea, vol. xxxix, p. 171, pl. xxi. figs. 24,25, 29, 30. The figure represents a young form belonging without doubt to the group of Pa~omutela Keyserlingi. The definition of the young specimens of this group is very difficult, because with age come considerable changes, l~evertheless, it is possible to say with certainty that the specimen here referred to is very similar to the young examples of Palceomutela Golowlcinskiana. I hope that in fuSure more forms will be found which will enable me to unite this African shell with P. GolowIcin~kiana. Dimensions: length 7, breadth 5, depth 4. Russian forms: length 114, breadth 7~, depth 4. P. Golowkinslciana is found in Russia in the Permian marls and sandstones of the Oka-Volga basin. Lovality. South Africa : Diamond mines at Kimberley.

PAr.m0MU1T_~A, cf. KErS~RLI~GX, mihi. (P1. XII. fig. 4.) 1892. PalwomutelaKeyserlingi, Amalitsky, Pala~ontographica, vol. xxxix, p. 168, pl. xxi. figs. 9-14. The South African form of this species differs from the Russian in its larger dimensions, which makes it approach more nearly the thick and large variety of Pal~omutela orthodonta, var. crassa (Palseont~graphica, vol. xxxix, p. 169, pl. xxi. figs. 22, 23), which belongs to the group of Palveomutela Keyserlingi. ,In Russia P. Keyserlingi is found at the upper horizons (A, B, C) of the Permian marls and sandstones at Nishny-Novgorod, and is especially frequent at horizon C. Dimensions: length 16, breadth 10, depth 8; Russian forms: length 12, breadth 7z~, depth 6. The above-mentioned P. orthodon~, var. crassa, measures : length 16, breadth 10, depth 8. Locality. South Africa: Beaufor~ Beds, at Graaf Reinet.

PAr,m0~UrSLA, cf. OVArIS, mihi. (P1. XII. fig. 8.) 1892. Pal~omutela ovalis, Amalitsky, Pal~eontographica, vol. xxxix, p. 169, pl. xxi. fig. 8. This badly preserved but typical internal cast bears a great similarity to the casts of Paheomutela ovalis, mihi. The impression of the hinge-line shows several small irregular teeth. In Russia .Pah~omuteht ovaZis is found in the Upper Permian marls and sandstones of the Oka-Volga basin, on horizon C at Nishny-Novgorod, and on horizon A at the river Vetluga. Dimensions: length 12-13, breadth 6zL7 , depth 5-6. Russian forms: length 16, breadth 10, depth 8. LocaZity. Soqth Africa: Graaf Reinet. Vol. 5 I.] r~Zssw~,~SR LASELLIBRASC~IATA. 345

Forms of the Group Palaeornutela Verneuili, PAL~OMUTELA SEMILUNULATA,mihi. (P1. XI[. fig. 10.) 1892. Palceomutela se~nilunulata, Amalitsky, Pal~eontoga'aphica,eel. xxxlx,p. 166, pl. xx. figs. 46-48. This is not a typical form of the group of Palaeorautela I'erneuili. The South African representatives are quite identical with Russian specimens. Paloe.o~nutelasemilunulata is found in Russia on horizons C and D of the Permian marls and sandstones of the Oka-Volga basin. Dime~sion.* : length 13, 15, 18 ; breadth 6, 7, 81z ; depth 2~, 3, 3~ (one valve). Russian forms : length 1;5--15 ; breadth 6-7 ; depth 2~-3 (one valve). Locality. South Africa: Graaf Reinet.

Forms of the Group Palaeomutela Murchisoni. PAr~.~OMUTELA MUaCHrSO~rr, mihi, ear. (PI. XIII. fig. 1.) Paleeomutela M urchisoni, Amalitsky, Pal~eontographica, eel. xxxix, p. 177, pl. xix. fig. 3'2. The African specimen of Palceom,~tela Murchisoni differs from the Russian tbrms described by me in possessing" a more obtusely developed ridge, which extends from the umbones backwards to the inferior-posterior angle. This distinction can only be of value when a now variety is established, but at the same time it brings this form into association with Paloeon~utela _plana, which belongs also So the group of P. M~erchisoni. Dimensio~ : length 18, breadth 10 ; Russian forms : length 24, breadth 13. In Russia Palwom~tela Murchisoni is found on the upper horizon B of the Permian marls and sandstones or' the Oka-Volga basin, near :Nishny-Novgorod and Gorbatoff. Locality. Karoo Beds at Bedford, South Africa.

PAL$OMVT~LA PLXr~, mihi. (PI. XIIL fig. 2.) 189s. Pala~omutela Tlana, Amalitsky, Pal~eontographica, eel. xxxix, p. 177, ph xxii. fig. 45. The African form of this species differs from the Russian forms only by its smaller size. Dimensions: leu~h 15, breadth 9; Russian forms: length 24, breadth 15. Paloeomutela plana is found in Russia on the upper horizon B of the Permian marls and sandstones of the Oka-Volga basin. Locality. South kfrica : Granf Reinet. PAL~OMUTFLA, cf. L~EVIS, mihl. (P1. XIII. fig. 3.) 1892. Palceomutola lagvis, Amalitsky, Pai~eontographica,eel. xxxix, p. 177, pl. xx. figs. 41-43. This badly-preserved but typical internal cast has a very groat 346 I'ROF. W. aMxI,xrsx~r o~ r~lx~,~r [Aug. 1895, likeness to the cast of Palceomutela ~vls from the Russian Permian, though without more material it would be somewhat premature to identify it with the Russian forms. Dimensions: length 4-5, .breadth 2-2~ ; Russian forms: length 9, breadth 5. In Russia Pal~eomutela lcevis is found on the upper horizon of the Permian marls and sandstones of the Oka-Volga basin, near Gorbatoff. .Locality. South Africa : Graaf Reinet.

PaL~.O~UTELA, sp. n. (P1. XIII. fig. 4.) Shell small, ovately oblong, convex, smooth ; umbones prominent, mesial obtuse, directed slightly forwards. The dorsal margin slightly curved, anterior margin rounded, posterior margin sloping somewhat obliquely backwards. The lower border is nearly straight. All angles are rounded. The surface has fine irregular concentric striations. I think that this form is perhaps a yourJg specimen of the group P. Keyserlingi. I cannot define it exactly, because sometimes the young forms of Palveomutela are very different from the adult stage. It is possible that this fbrm wilt subsequently prove to be a young specimen of P. triejo~alis. Dimensions: length 7, breadth 5, depth 4. .Locality. South A~rica: Diamond mines at Kimberley.

PALMANODONTA, n. g. 185~. A~odonta, Forbes, Mere. Geol. Surv. Irel. Expl. Sh. 147 and 157, p. 16 (A. Jukesii). 1859-1863. Anod~mta,Ludwig, Pakeontogl"aphica,vols. viii., ix., xi. 1861. Anodonta, Geinitz, ' Dyas.' 1868-1878. Naiadites, Dawson,pars, ' Acadian Geology,'2nd and 3rd eds. pp. 204-- 205.~ 1892. Naiadites, Amalitsky, Pal~ontographica, vol. xxxix. 189~. IVaiadites, Netshayeff, 'Die Fauna der permischen Ablagerungen des 5stlichen Theils des europi~.ischenRusslands.' 1894. Carbonicola, Wheelton Hind (pars : only edentulous forms), Pakeont. Soc. vol. xlvi. Diagnosis. Shell equivalve, inequilateral, elongated or oval, unioniform, smooth. Ligament external, situated behind the umbones. Hinge-margin toothless, curved, angulated or straight, sometimes thickened. The scars of the adductors are strong, oval, or elongated ; the small scar of the pedal muscle is separated from the anterior adductor and situated under the hinge-line; very rarely a supplementary small lunate scar is situated behind the anterior sear of the adductor. Pallial scar entire. Valves closed. The type is Palaeanodonta Castor, Eichw., sp. For synonymy, etc., see my paper, ' Ueber die Anthracosien der Permformation Russ- lands,' Pal~eontographica, vol. xxxix. (1892) p. 192, pl. xxii. figs. 40-43. a A discussion of the synonymy of .5Taiadites, Dawson, which is contained in Dr. Wheelton Hind's papers, Quart. Journ. Geol. See. vol. xlix. (1893)and vol. 1. (1894), will be published in a subsequent memoir. ~oL 5 i.] rRESitWATER L.IMELLIBRANCHIATA. ~347

Horizons.--Freshwater deposits of the , Carboniferous, and Permian systems. In studying the Carboniferous and Permian Anthracosid~e in 1892, I found it impossible to retain the Palaeozoic forms described by Forbes, Ludwig, and Geinitz as A~odonta, but included them under the generic name of .Naiadites, Dawson. My reason for adopting this was that Dawson, under the term Naiadites, described and figured six forms (' Acadian Geology,' 2nd & 3rd eds.), ~ which he named:--N. (Anthracoptera) carbonaria, N. (Anthracomya) elongata, N. (Anthracoptera) l~vi~r 1V. arenacea, _hr. ovalis, IV. angu- lain. Therefore we see that Dawson's IVaiadltes includes three groups of organisms : Modiola-like Anthracomya, Salter (1861), and Anthracoptera, Salter (1863), and Anodonta.like properly Naiadite~ (N. arenacea, iV. ovalis, IV. angulata). Salter having already established the generic names Anthracoptera and Anthracomya for the first two groups, I substituted .u only for the last--that is, for the Anodonta-like shells. But Dawson, according to Dr. Wheelton Hind, ~ and in a more recent paper, 3 considers it best to drop out Salter's genus AnthracoTtera (1863) and replace it by !Vaiadites. The third group, the Anodonta-like shells ( N. arenacea, IV. ovalis, N. an- gulata), which at first he held to be true 2Vaiadites, he considers now as follows: the two species iV. arenacea and ~. ovalis he refers to Anthracomya, giving them different diagnoses and drawings ~ from those that he had previously given, and one species (N. angulata) he refers to Anthracosia. In consequence of this the Anodonta- like forms, which I describcd iu 1892 as 'lVaiadites, Dawson,' remain now without a generic name, so that I venture to establish for them the new genus Paheanodonta. This differs from Anthracomya, Salter, (1) by having equivalve shells always closed at both ex- tremities ; (2) by having a narrow posterior end (in typical forms) ; (3) by its curved, angulated (seldom straight) hinge-line; (4) by the disposition and shape of the muscular scars being quite similar to those ia Carbonicola, :M:'Coy, Anthracosia, King, or .Pala~omutela, mihi.

1)A~Y_~ODONTA OK~SSIS, mihi. (P1. XII[. fig. 6.) 1892. Naiadltes okensis, Amalitsky, Pal~eoutographica, vol. xxxix, p. 193, pl. xxii. figs. 26-29. This shell agrees completely with the diagnosis and the original specimens themselves of this species, which are iu my possession, from the ~ermian marls and sandstones at ~ishny-:Novgorod, horizon C. Dimensions : length 17, breadth 18 ; Russian forms : length 20, breadth 10-11. Locality. South Africa : Bloemkop, near Grant Reinet. l See 1)I. XIII. figs. 7-10, 12, 14. 2 Quart. Journ. Geol. Soc. vol. 1. (1894) p. 437. a Canadian Record of Science, Oct. 1894, ' Rvv. of the Bivalve of the Coal-Formation of ~ova Scotia.' See Pl. XIII. figs. 11 and 13. 348 1PROf. w. a~a'sx~ oz~ r~'mlia.~ [Aug. I89~,

PAr.~A~o])oN'rA SUBCASa'OR, mlhi. (P1. XIII. fig. 5.) 18~. a~~ s~ssCor, Amm$it~y, Palaumtogr~hiea, voL XZliX. 1~ 191, pl. xxii. figs. 30-33. 1894. )Vaiadite# subcastor, Netshayeff, ' Die Fauna der permischen Ablagerunge~ des 5stlichen Theiles des europiiisehen Russlands.' The South A~rican shells determined as this species conform fully to the diagnosis of Paheanodonta subcastor, and are especially like the forms ibund near Gorbatoff, Oka river, on horizon ]J of the Permian marls and sandstones of the Oka-Volga basin. This species occurs on all the horizons of the Permian marls and sandstones of Eastern Russia. .Dimensions: length 21, breadth 10, depth 8; Russian forms: length 19, breadth 10, depth 6. .Locality. South Africa : Graaf Reinet.

EXPLANATION OF THE PLATES. PLATS XII. Fig. 1. Ta~omutela rhomboidalis, Sharpe, (}raaf Reinet. 1 a, lateral view ; 1 b, showing striated hinge-margin. Sharpe's original specimen. 2 a, b. Pa~omutela rhomboidalis, Sharpe. Bloemkop. 3. Pal~eomutela, sp. Graaf ]~einet. The original specimen for Sharpe's description of the hinge of Iridina (?) ovata. ;~ a, natural size ; 3 b, enlarged, and showing transversely-striated hinge-margin. 4 a, 4 b. Pal~omutela, el. Keyserlin.qi, mihi. GraafReinet,. 5. Paleomute/a, n. sp., aft. orthodonta, mihi. Diamond mines at :Kimberley." 5 a, showing the external view ; 5 b, showing badly-preserved hinge- line. 6 a-f. Palceomutela trigo~uzlis, mihi. Diamond mines at Kimberley. 7 a-e. Pal~omutela, n. sp., aft. Golowkinskiana, mihi. Diamond mines at Kimberley. 8. Pal~omutela, cf. ovalis, mihi. Graaf l?~einet. 9. Pal~eomutela, Bp. Diamond mines at Kimberley. 10. Pal~eomutela semilunulata, mihi. Graaf Reinet. 10 a-d, external view ; 10 c', showing the hinge-margin ; l0 d', hinge-margin, natural size ; 10 d", enlarged; 10d'", hinge~margin from above.

PLATE XIII. Fig. 1. Palmomutela Murchi,umi, mihi, var. Bedford. 2. Pabeorautela plans, mihi." Graaf l~einet. 3. Pal~omutela, cf. l~evis, mihi. Graaf Reinet. 4. Pala~omutela, sp. n. Diamond mines at Kimberley. 4 a, b, lateral view ; 4 e, ftx)m above. 5. Pal~eanodonga subcaslor, mihi. 5 a, lateral view; 5 b, hinge-margin. Graaf Reinet. 6. Pal~a~oclonta okends, mihi. 6 a, b, from Graaf 1Reinet ; 6 e, from Bloemkop.

Copies of Drawings of Naiadites, Dawson. Fig. 7. 2r (AnthracoT~era) carbonaria, Dawson (' Acadian Geol.' 2nd ed. p. 204, fig. 42). 8. ~aiadites (Anthraaom~a) elongata, Dawson (ibid. t~g. 43). 9. ~aiadites (Anthracoptera) lxvi~, Dawson (ibid. fig. 44). 10. Jgaiadites arenacea, Dawson (ibid. fig. 45). Vol. 5t.] P~rsaWXrEa T.AaE~B~CaIXTX. 349

:Fig. 11. Anthraeomya arenazea, figured by Dawson as a synonym of the above- mentioned .Yaiadites arenacea (' Review of the :Bivalve Mollusca of the Coal-Form. of N. Scotia,' p. 12, fig. 10 l). 12..Naiadites o~lis, Dawson (' Acad. Geol.' 2nd and 3rd eds. p. 205, and Quart. Journ. Geol. See. vol. x. 1854, p. 39, fig. 24). 13. Anthracomya ovalis, figured by Dawson (' Re~. of the Bivalve Mol~uJca,' etc. p. 13, fig. 11) as a s)~aonym of the above-meatiaaed 2V'aiadites ovalis, Dawson. 14. ~aiadites angulala, Dawson, ' Acadian Geology,' 2nd ed. p. ~ fig. 46.

DISCUSSION, The PRESIDlS~T bore testimony to the value and importance of the work carried on by Prof. and Mine. Amalitsky in describing and figuring the various species of lamellibranchs from the Coal Measures and the Pormo-Carboniferous strata of Russia and else- where. The present paper dealing with the African species was the result of several months' work on the British Museum Collection and in that of the Geological Society. He trusted that careful attention Would be given to the question of synonymy, and pointed to the valuable list drawn up by Mr. E. T. Newton, F.R.S., in the Quarterly Journal for 1894, attached to Dr. Wheelton Hind's paper. Prof. H. G. S~LEr stated that in St. Petersburg he had gathered from Dr. Karpinsky that the pal~eontological evidence was slender for determining the age of the Permian deposit which yields Rhopal-- eden and Deuterosaurus. Beneath that deposit there is a bed termed ' Permo-Carboniferous,' which also yields a few anomodont bones. And somewhat higher in the series are fish-remains of the type of Acrolepis, common to Permian and Tries. Many of the bones that he had studied were from a marine bed full of Modiol-. ojosi8 Pallasi and a species of Terebratula. The superficial resemblance in dentition between the Russian Permian reptiles and those of South Africa was misleading; for while both belong to the therosuehia, the African theriodontia all have the coronoid process of the dentary bone much elevated, and the hard palate terminates in a transverse edge behind which the palate-nares descend; while in the Russian deuterosauria the coronoid process is not elevated, and the palate-nares open as ovate vacuities, as in the palate of nothosaurs and plesiosaurs. It was therefore remarkable to find that the freshwater shells of the Karoo rocks were determined as identical with those of the Permian of Russia; notwithstanding the well-known persistence of freshwater shells in geological time, with little change. The Karoo Beds are of immense thickness, and their outcrop covers about 70 miles of breadth. About 20 miles north of the base, following the dip, the one example of shells occurred which Was known in the Colony, at the base of beds yielding Pareiasaurus. He thought that all the African beds which contain anomodontia are probably Permian, and the upper beds of the Karoo System

i Canadian Record of Science, October, 1894. 350 PEItMrAN FREsH,rATER LAMELLIBRANCH8 [Aug. I~9~ , were so classed in his account of the theriodontia, communicated to the Royal Society. There are traces of coal at the base of the Karoo system, more in the middle and most at the top, where the Indian genera Tceniopteris and others are found. Above these are the Stormberg Beds, which he regarded as Trias, which yield dino- saurian reptiles (saurischia) closely allied to those of the Trias of Europe. He thought it an advantage to have evidence from an invertebrate group of upon the age of the beds; and the results represented patient and careful work. Dr. BLANFOm~ said that the Karoo series of South Africa com- prised beds ranging in age from Carboniferous to Middle Mesozoic, prubably ; and Prof. Green, in the discussion on his paper in the Society's Journal for 1888, had found himself unable to determine what the Beaufort Beds were. The flora found in the lower stages of the Karoo Beds of South Africa, like that in the Lower Gondwtlnas of India, and that in the :Newcastle Beds of Australia, differed so completely from that found in strata of the same age (Carboniferous and Permian) in Europe as to indicate that the Northern and Southern land-regions throughout Upper Palaeozoic times were completely isolated from each other. If, then, the mol- luscs described by Dr. Amalitsky came from beds of Permian ago in Russia and South Africa, and were identical or closely allied, it would be a question whether those mollusca were not marine or estuarine rather than freshwater. No traces of any similar bivalves had been found in the Gondw~na system of India, the beds of which, on account of their economic importance, had been very thoroughly searched for fossils. Prof. T. RUP*'RT Joz~s said that the Society was to be con- gratulated on receiving an account of Prof. Amalitsky's researches on these African and Russian fossils--whether of , Permian, or Permo-Carboniferous age. The Author was carefid in speaking of their homotaxis rather than contemporaneity. Those from South Africa had come from places far apart---namely, Graaf Reinet, Kat Itiver, Kimberley, and the north-western border of Lake Nyassa. He thought it possible that they may have been of estuarine (or salt-lake) rather than of river-origin. He particularly alluded to the excellent and exact drawings of the most noteworthy of these little fossils, made by Mine. Amalitsky for comparison with those of Russia. Mr. E. T. NEw~os made some remarks on the synonymy of _Naiadites. Mr. R. B. N~.wro~r thought that there should be no difficulty in accepting the Author's new generic name of Palceanodoma for the three forms described by Sir 3. W. Dawson in 1860 as Naiadites arenacea, iV. ovalis, and 2r angulata, which differ so widely from the type of the genus (2r carbonaria), and which had also been wrongly referred by Dr. Wheelton Hind (1894) to Anthracomya and Carbonicola. The Author's synonymy of this new genus would be better explained by the introduction of the word pars after '.Naiadites, Dawson, 1860.' Mr. G. F. HAl~mS observed that that portion of the.paper which Vol. 5i.] ~so~ RUSSIA A~D SOVTH aarRICA. 35I: dealt with correlation depended in a great measure on the correctness of the Author's identification with the Zechstein of the Russian fresh- water beds alluded to. It would have been better, perhaps, to hav~ omitted the evidence afforded by the vertebrata, seeing that Russian geologists were not in accord as to the precise age of the deposits in which these occurred. The excellent work done by Prof. Amalitsky with reference to the genera _Pal~eomutelaand Palveanodonta, and the successful manner in which he had shown that Russian freshwater lamellibranchiata were represented, almost specifically, in the Karoo Beds of Africa, were points for congratulation. It might be remarked, however, that the Author's views as to what constituted a species in the Anthracosid~e and their allies were rather broad--a circumstance which might have assisted him in recognizing a closer relationship between the European and African mollusca alluded to than would otherwise have been the case. The Author had been extremely careful in drawing up the generic synonymy of certain forms described by Sir J. W. Dawson, and this paper would set at rest many hitherto doubtful matters in that connexion. Altogether, it was a very valuable and important communication.

Q.J.G.S. No. 203. 20 Quart .Journ.Geol. Soc .1/ol. LI. P1.XIi.

A.~Ii~81~ del. 1=. H. l~c1~a.el Iztl~. ~rrLBros.rrn~. P_A/~]]s OMU T ELA Qua.rt.Jo~rn. C~ol. So(:. Vol. LI. Pt, XIII.

PALA~OMUTELA A/qD PA_L]EA~OD ONTA AIND REPRODUCTIONS OF [NAIAI)ITES,[ETC.