74 PROCEEDINGS OF THE MALACOLOGICAL SOCIETY. 



Chione, Claimnella, and Anaitis.^ In 1902 Dr. Dull gave V. pUcata 

 as the type of Circomphahis, but without reference to Sacco or to 

 anyone else- in explanation of such a selection.^ 



It is much to be regretted that the name should thus come to be 

 attached to V. plicata '\n?>tQix.d. of to some member of the ^m/-« group, 

 for which it was evidently intended both by Morch and by H. & A. 

 Adams. Tiiey only included V. plicata in that group because they 

 supposed it to resemble the rest in having no lateral teeth, or 

 because they did not regard the small anterior tubercle as a normal 

 tooth. 



Neither V. lamellata nor V. calophylla can be grouped with V. plicata, 

 for neither of them shows any trace of an anterior lateral even in very 

 young shells, and through the kindness of Dr. J. C. Verco, of Adelaide 

 (S.A.), I have been able to examine young shells of both these species. 

 Another shell which much resembles V. plicata in external characters 

 is V. yate-si, but the specimens which I have seen show no trace of 

 an anterior denticle. Indeed, so far as I can ascertain there is no 

 other recent species which can be associated with the type of 

 Circomphalus. There are, however, several species in the Miocene 

 and Pliocene deposits of France, Italy, and Austria which certainly 

 belong to it ; these are V. subplicata, d'Urb., V. basteroti, Desh., 

 V. dertoparra, Sacco, and V. scalaris, Bronn. Ey Messrs. Cossmann 

 and Peyrot these species have been referred to the Clausinella section 

 of Chione, but that must be reserved for the shells which have no 

 rudiment of a lateral tooth, as there is none in C.fasciata which is 

 the type. The other species which they associate with V. plicata 

 I should refer to Ventricola ; these are V. casinoides, V. fasciculata, 

 and V. haidingeri. Professor Sacco has figured many varieties of the 

 above-mentioned species, but I do not think he has correctly referred 

 all his specimens to their proper species, for he evidently regards the 

 anterior denticle as of no importance even in the distinction of 

 species. 



I am quite prepared to admit tliat the fasciata and tiara group has 

 probably been derived from the plicata group by the elimination of 

 this anterior lateral, but I regard the retention of the lateral tooth 

 as a feature of generic importance. This question will be further 

 discussed in the sequel. 



1 I Moll. Terz. Piem., pt. xxviii, 1900. 



2 Proc. U.S. Nat. Mus., vol. xxvi, p. 356, 1902. 



