fial synonymy and bibliography in 1 he u .lahrbiichcr der 

 Dentschen MalakoZOOlogischen <;c-cIUcha.ft " fur the same 

 \ car. 



According l.o Woodward, ( .)7 fossil species li;i\ e been deter- 

 mined. 



The subdivision of the Cypneidse into groups, is attended 

 with considerable diflirnlty, inasmuch :is many of the species 

 which appear distinct when the types only of each :ire compared, 

 are found !> lie closely connected by intermediate forms. For 

 instance, t.-ike the scries of shells of which (',. xtu/>/ii//H-a :uid ('. 

 l>'tlil<i :ir- the ext i-eine e\:iinples : 



'I'he forinei- is d:ii-k in color, pnst uhitc, :ind the teeth extend 

 enliiely over the l>:ise of the shell, in the form of ridges, while 

 the hitler is cre:ini-t inted, perfectly smooth, the teeth heinii' con- 

 lined to the ni:ir<j,in of the :ij>ertiire e\ce|)t for a short distnnce 

 at the ext Trinities of the eolimiell.M, :ind I do not hesit.-ite to 

 place it in the same uronp with the l>e:mtifiil ('. Li^trri, (Jr:iy. 

 Yet it is possible t> connect them. The s:ime m:iy he said of 

 m.-iny other well reco-nixed antipodal sj)ecit-s. A^ain, local 

 causes have produced variations in well-known species and these 

 have received new names, thereby swelling the synonymy. This 

 18 noticeable in the case of the New Caledonian forms which 

 frequently occMir rostrate and show a tendency to melanism. 

 < v )nite in cont ra>t is this with t he pale coloring exhibited in num- 

 erous Sandwich Islands specimens of other well-known species. 

 It has been observed that the pale coloring peculiar to the 

 shells from the latter locality, is confined to the ( 1 ij [>r;< i<ln. 



Of the New Caledonian forms, over forty species are found 

 at Mauritius, and Dr. .I oiisseaiimc remarks as a consequence 

 that this representation in so widely separated and completely 

 isolated localities is not in accordance with the views of the 

 advocates of ideographical provinces. 



Various classifications have been proposed, t he most promi- 

 nent heino those of (I ray, II. and A. Adams, Sowerby , Troschel, 

 Wcinkanir, and .I oii^seaume. 



Dr. (Jray recoo-ni/.cd six genera: Cypra-a, Lnponia, Cypneo- 

 vnla. Trivia, Mrato, Ovnlnm; subdividinu' the first into sub- 

 ii'enera C\ pra-a, Aricia. Naria. 1 1 is dcscript ions areas follows: 



