president's address. 77 , 



Dendropupa Walchiarum, Fischer. Middle Permian. 

 Dendropupa Walchiarum, Fischer: Journ. de Conch yl., torn, xxxiii 



(1885), p. 100, fig. 



Dendropupa prim^va (Matthew). Upper Devonian. 

 Pupa pervetus, Matthew ; n.n. Dawson : Trans. Roy. Soc. Canada, 



vol. xii (1895), sect, iv, p. 84. 

 Pupa primceva, Matthew : loc. cit., p. 98, pi. i, figs. \Qa and h. 



Anthracopupa Ohioensis, Whitfield. Upper Carboniferous. 

 Anthracopupa Ohioensis, Whitfield: Amer. Journ. Sci., scr. iir, 



vol. xxi (1881), p. 126, figs. 



Anthracopupa Vermilionensis (Bradley). Upper Carboniferous. 

 [Mentioned, but not by name] Bradley : Eept. Geol. Surv. Illinois, 



vol. iv (1870), p. 254. 

 Pupa Vermilionensis, id.: Amer. Journ. Sci., ser. in, vol. iv (1872), 



p. 87, fig. ; Dawson, op. cit., vol. xx (1880), p. 410, figs. 



The fact that a European example of a Palaeozoic Land Snail has 

 been found, albeit of a later age than the described American ones, 

 should encourage research in this country, where doubtless, when 

 looked for in likely situations, examples will also be found. 



Another early form of Gastropod calls for mention here, and that is 

 Sercynella, because by some authorities it has been placed with the 

 Siphonariidse on account of the curious fold running from the apex to 

 the margin of the patelliform shell. Now Pelseneer has pointed out 

 {IfO, p. 67) that Siphonaria is a Basommatophore that has secondarily 

 become adapted to a marine life. With such an origin an example is 

 hardly likely to be found so early in the geological sequence as the 

 Devonian ; even Anisomyoji, from the American Cretaceous, seems 

 doubtful, and unquestioned examples only come in with the Tertiary 

 period. Moreover, a careful scrutiny of the most recent figures 

 (Pernor, 1^2, torn, i, pis. xliv-1 ; tom. ii, pis. cv, cxviii-cxxiii) 

 does not give at all the impression that Scrcynella belongs to the 

 Siphonariidge ; indeed, the characteristic fold partakes far more of the 

 channel observable in Siibemarginula, near which it has been placed 

 by some palaeontologists. Fischer {llj., p. 861) inclines to ally it 

 with Capidus, and consequently Platyceras. Probably it woulcl be 

 most correctly placed as an aberrant form of the then decadent 

 Prostreptoneura, but further evidence is required. 



The past history of the Gastropod branch of the Molluscan phylum 

 is on the whole, therefore, less consonant with their morphological 

 genealogy than is seen to be the case in the Cephalopoda and Pclecypoda. 



There remains now the class Amphineura to consider. 



These molluscs are generally held to be a very primitive group, and 

 Pelseneer shows them to be the most archaic of recent Mollusca, and 

 derives from them all the other classes save the Cephalopoda {39, 

 pp. 1-41 and 82). Hence, to accord with their morphological position 

 they should have been the oldest mollusc geologically. This, however, 

 is not the case, and they are not met with in any strata older than 

 the Ordovician, when the genus Priscochiton makes its appearance, 



VOL. VIII. — JUNE, 1908. 7 



