Subfamilies, Genera, and Subgenera — Recent and Fossil 95 



Shell (of Anisopsis ccdcidus (Sandberger) , plate 81, fig. 10 ». 'Testa cal- 

 culiforinis, superne excavata, inferne latissime uinbilicata. Anfractus 3^/4, 

 gracilis, quadrangulates, superne excavati, ad margineuni sui)erum necnon 

 ad iimbilicuin carina cincta, suturis tenuibus profundis disjiincti, costulis 

 trans versalibus subtilibiis ornati, ultimus permagnus, spiram eminens 

 (Sandberger, p. 14). Taf. 1, fig. 7, 7a (stark vergrossert).' 



The shell is ultradextral, with a distinct, sharp carina in the middle of 

 the whorls on the right side. The left side also has carinated whorls. The 

 whorls are few in number, increasing rather rapidly in diameter. From the 

 figures there appears to be a carina at the periphery. 



Horizon and Distribution. Middle or brown Jurassic period. Cajac, in 

 layers e and f. Very rare. 



Remarks. The name Anisopsis appears to be a nude name, no type hav- 

 ing been formally designated for it, as far as the writer is aware. It also 

 appears to have been comparatively unnoticed by recent students of the 

 Mollusca. The only American reference observed is that by Dall in 1905, 

 who cites Planorbis loryi Coq., and Planorbis calculus Sandb. as examples. 

 The original reference is in a stratigraphic table on page 958 of Sandberger's 

 work in which Anisopsis appears between Bathyomphalus and Anisus. The 

 only valid reason for associating the two species mentioned above with 

 Anisopsis is the presence of the stars in the Aliddle ( ]\Iittlerer) Jura and 

 the Upper (Oberer) Jura in the table, indicating that these two species 

 are the ones intended for this group name, since no others from these 

 horizons occur in the body of this work. 



Planorbis calculus Sandberger occurs first on page 14 and should be 

 taken as the type of Anisopsis. On page 15 Sandberger mentions the like- 

 ness of this sj^ecies to the tricarinate Valvatas of North America typified 

 by Valvata tricarinata. The figure of this species does look much like 

 Valvata tricarinata on the right side but on the left side the figure is too 

 wide, lacking the distinct carina and deep umbilicus of the American 

 Valvata. Dall (1905, p. 81) suggests its relationship to Helisoma but the 

 left side is different from any species of that genus known. The exact size 

 is not given by Sandberger, who states that the figure is much enlarged. 



The second species, Planorbis loryi Coquand (Sandberger, p. 41) is 

 more planorboid in form and somewhat different in shape from calculus 

 (see plate 81, fig. 11). It is also larger. Sandberger suggests its resemblance 

 to Planorbis complanatus (Linn.) (=jontanus Lightfoot) and Planorbis 

 carinatus Miiller, but the figures do not resemble either of these species. 

 Sandberger's description of this species is as follows: 'Testa calculiformis, 

 su])ernc profunde excavata, inferne depressa, latissime umbilicata. An- 

 fractus quinque. gracilis, costulis transversalibus tenuibus muniti et carinis 

 duabus acutis insignes, prima partem su})eram excavatam, altera basin 

 cingente. Apertura trapezoidea, valde iniquilateralis.' 



The horizon and localities for this species are given as follows by 

 Sandberger (p. 41) : 'Villers le Lac (physaschicht b), les Rousses, Charix 

 bei Nantuar, Alferme und Vigneules am Bieler See in den gleichen Schich- 

 ten.' These localities are in the Upper or White Jura. 



The group Anisopsis, which may be designated as a genus of the sub- 

 family Planorbinae, may be retained to contain these early fossil species. 

 The two species referred to this genus may not be congeneric, loryi appear- 



