OF SOUTHERN INDIA. . 87 



showing tlie impressions of the teeth of Panopma, and therefore belong to the last genus and not 

 to Fleurom.ya. Our materials are not sufficient to allow of our inquiring into this statement^ but it 

 seems quite certain that in many of the cretaceous Panopce^ 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 Fanopcece there are many 

 Homomym, FleuromycB, and even Poromyce. 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 Panopcea as is to be 

 seen on Panop, neocomiensis and some other species. Besides this several lower cretaceous species 

 are so very similar to each other^ that one would be inchned^ 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 indispensable and certainly very desirable, for to settle these generic diff'erences 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., Robinaldina, d^Orb., 

 Alhertina, d^Orb., {^Qrh^^^^cylindrica, P. and C), accuUisiodorensis, Cott., rostrata, Math. 

 (==:arcuata, d'Orb.), lateralis, Ag., irregularis, d'Orb., Cottaldiana and Carteroni, d'Orb., lata, 

 aitenuata and curta, Kg., cylindrica, P. and C, Bupiniana, d'Orb., Voltzii, Urgomnsis, Massiliensis 

 {^(^^=attenuata), cuneata (?:=^lata), 



22-27.— Eichwald (Leth. Eoss., 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 

 Lepec'heniana,^'Ox\i, The same author also quotes neocomiensis {=Orbignyana, Rouillier), /^^«, 

 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 plicata. Sow.), P. nana, fallax and 

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

 Poromym. Coquand also quotes plicata, %o^,, from Spain, and identifies ^om^^' ^ plicata ^'\i\i 

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

 Brongniart-'s gurgitis and most likely a Pleuromya. 



32-40.— (Gault species) ; P. Romeri, (^ein., acutisulcata, J) Q^h., plicata. Sow., (is more inflated 

 than diOYhignys plicata, which also has the anterior side a little longer, in which respect it resem- 

 bles acutisulcata, of which Piet. and Camp, suggest it may be only a variety), Arduennensis, 

 Constanta (? Pleuromya) ^VL^incEqualis, d'Orb., 8auhadiana,V. ^-^^ R, ( ? Poromya) , 2.Ti^Ehodani, 

 Pict. and Eoux (Foss. gres. vert., p. 400, omitted in the Prodrome and consequently also in Pictet 

 and Camp. ^s list). 



41-54.— (Middle and upp. cretaceous species); P. mandibula (=Beaumontii,'MviXi^i.=Iugleri, 

 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 represent a shell which could possibly be 

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

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

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

 Goldfuss'i?^it?«2^^, and most likely will have to receive a new name]. P. laviuscula Siudi ovalis, 

 ^ow. ^"^.j suhstriata, ^'Oich.,{^ Pleuromya! ); Asteriana, d'Ovh. (sl Poromya ! ); elatior, regularis 

 2ind Normaniana, d'Orb,, cretacea, Math., elongata, E6m. (non i^^^z^. \^? Panop cBa'\ elongata, Miinst. 

 from the oolite) ; Ewaldi, Eeuss, (is very like Matheron's cretacea)-, sinuata, Eeuss; 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. 



