OF SOUTHERN INDIA. 87 



showing the impressions of the teeth of Panopaea, and tlierefore belong to the last genus and not 

 to Pleuromya. Our materials are not sufficient to allow of our inquiring into this statement, but it 

 seems quite certain that in many of the cretaceous Panojxea the shell is much thinner than 

 in any recent species of that genus, and the strong fulcra supporting the ligament are sometimes 

 perfectly wanting. I am rather confident that among these cretaceous Pano^ieea there are many 

 Komomyce, Pleuromya, and even Poromym. To quote only one instance : I certainly do not know 

 where such a finely striated and punctated surface is to be observed on a recent Panopaa, as is to be 

 seen on Panop. neocomiens'is and some other species. Besides this several lower cretaceous species 

 are so very similar to each other, that one would be inclined, from the existing descriptions and 

 figures, to reduce them to at least one-half the present number. Most of them have been examined 

 by Pictet himself, but apparently not with much success; the examination of the originals is in this 

 case indispensaljle and certainly very desirable, for to settle these generic differences would be a great 

 gain to conchology; it would also extremely facilitate the determination of our mesozoic Myacea. 



3-21. — (Neocomien species); P. Neocomiensis, Leym., arcuata, Ag., Rohinaldina, d'Orb., 

 Albertiiia, d'Orb., (perhaps^cy^/^^/'iM, P. and C), accutlisiodorensis, Cott., rostrata, Math. 

 [=arcuata, d'Orb.), lateralis, Ag., irregularis, d'Orb., Cotlaldiana and Carteroni, d'Orb., lata, 

 atteiuiata and curta, Ag., cylindrica, P. and C, Biipi/iiana, d'Orh., Voltzii, Urgoiieiisis, Mussilieiisis 

 {J^:z^aitenuata), cuneata (?^lata). 



22-27. — Eichwald (Leth. Ross., livr. XI, p. 777, &c.,) quotes from the Neocomien (Jurassic in 

 part) P. peregrina, d'Orb., Keyserlingi, d'Orb., horealis and antiqua, Eich., Qualeneana and 

 Lepecheniana , d'Orb. The same author also quotes neocomiensis {=^Orbignyana, Rouillier), lata, 

 Prevostii, acutisulcata, lateralis and carteroni, the last from cenomanien beds and the preceding 

 simply from a ' cretaceous marl.' 



28-31. — (Aptien species) ; P. Prevostii, Desh., d'Orb., (non pUcata, Sow.), P. nana, fallax and 

 Aptiensis, Coquand (fitage Apt. de 1' Espagne, 1865, pp. 89-90, &c.). The last two species may be 

 Poromym. Coquand also quotes pUcata, Sow., from Sjxiin, and identifies Romer's plicata with 

 Leymerie's neocomiensis, which I do not think at all correct, that species being possibly the same as 

 Brongniart's ^!<r^i7i« and most likely a Pleuromya. 



32-40. — (Gault species) ; P. Rbmeri, Ge'm., actdisulcata, Desh., plicata, Sow., (is more inflated 

 than d'Orb igny's^//ca/'«, which also has the anterior side a little longer, in which respect it resem- 

 bles acutisulcata, of which Pict. and Camji. suggest it may be only a variety), ArJuennensis, 

 Constanta ff Pleuromya) and inaqualis, d'Orb., Saudadiana, F. and R., ( ? Poromya) , andRliodani, 

 Pict. and Roux (Foss. gres. vert., p. 400, omitted in the Prodi-ome and consequently also in Pictet 

 and Camp.'s list). 



41-54. — (^liddle and upp. cretaceous species) ; P. mandibula (=Beaumoniii, M.un&i.'= Jugleri, 

 Romer; I think Geinitz is correct in identifying these); gurgitis, Brong. [this is said by Pictet 

 and Campiche to have been based upon a species from Perte-du- Rhone, and may prove to be the 

 same as neocomiensis ; Brongniart's figure certainly does not ref)resent a shell which could possibly be 

 neocomiensis, though he may have applied the name to such a form. Romer's P. plicata is similar 

 in form to Brongniarfs gurgitis, but is less high posteriorly and the surface is punctated; it more 

 likely belongs to Pleuromya. D'Orbigny's and Reuss' P. gurgitis is to all appearance the same as 

 Goldfuss'^^/ca<a, and most, likely will have to receive a new name]. P. laviuscula and ovalis. 

 Sow, STp., subsiriata, d'Ovh., (a, Pleuromya!); Asteriana, d'Orh. (a Poromya ! ); elatior,regularis 

 z,nd Normaniana, d'Orb., cretacea. Math., elongata, Rom. {non Liit. \_.'' Panopaa'\ elongata, Miinst. 

 from the oolite) ; Ewaldi, Reuss, (is very like Matheron's cretacea); sinuata, Reuss; Goldfussi, 

 d'Orb. ; this last name was suggested for the species described by Goldfuss as gurgitis, (Brong.) 

 and which appears to be identical with Nelson's species of the same name; both are a good deal like 

 plicata, Sow, 



