president's address. 75 



In this little gi'oup of Palaeozoic air-breathers we have the earliest 

 terrestrial llhipidogiossate, if we accept, as I think we may do, 

 Whitfield's determination of Bawsonella as such, the oldest known 

 AmpuUaria, for Walcott's "?" seems unnecessary, and the first of 

 the Pulmonates. 



Both divisions of the last-named order are represented, the Basom- 

 matophora by Physa and Zaptychms. The determination of the Physa 

 is probably correct, for one would hardlj' look for so highly differentiated 

 a form as a sinistral Limncea at so early a period in the world's history ; 

 moreover, Physa is the more primitive of its congeners, its radula being 

 less specialized than those of Limncea or Planorhis, both of which are 

 met with far later in the record of the rocks. 



ZaptycMus, however, connotes an older family, since, according to 

 Walcott — and our Editor, Mr. E. A. Smith, agrees in that opinion — 

 it "appears to have its nearest ally in Atiricula.^^ Pelseneer holds 

 (57, p. 114; 1^0, p. 66) that the Auriculidae are nearest akin to 

 the Opisthobranchs and arc consequently the most archaic of the 

 Pulmonates, and present the greatest number of characters common 

 to both Basommatophora and Stylommatophora. By right, there- 

 fore, they should make their appearance earlier in the geological 

 sequence than the more specialized Stylommatophora. This they 

 Just fail to do, for Dawson's Stroplutes, although fragmentary, 

 certainly seems to belong to the Pupidse, although not identical, as 

 he subsequently appears to have thought, with Stroplua — Cerion as we 

 now know it. 



The remaining Pupidae — for such they probably are, unless, like 

 Sphyradium, the Bendropupa group belongs really to the Endodontidae — 

 fall into two divisions, those with and those without teeth, neither of 

 which can it be pretended is identical with Pupa itself.' It seems, 

 therefore, most reasonable for the present, till further material shall 

 be forthcoming, to provisionally range the edentulous species under 

 Bendropupa, and the dcntigerous under Anthracopupa. 



It may facilitate purposes of reference if the information here 

 gathered concerning these Palaeozoic Pulmonates be summarized as 

 follows : — 



HELICINID^. 

 Daavsonella. MEEKr, Bradley. Upper Carboniferous. 



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



vol. iv (1870), p. 254. 

 Anomphalus MecJci, Bradley : Amer. Journ. Sci., ser. iir, vol. iv 



(1872), p. 88, fig. 

 Bawsonella Mcehi, Bradley: as a helicoid, op. cit., vol. vii (1874), 



p. 151 : belongs to Helicinidae, Whitfield, op. cit., vol. xxi 



(1881), p. 127, figs. 



Dawson's comparisons with recent forms do not seem altogether happy ones. 



