242 NEW FOSSIL SHELLS 



Remarks. This shell is rounded and more globose than any of its congeners that 

 I have seen. These characters will serve to distinguish it from all our other fossil 

 species. 



GENUS VENUS. 

 V. ASCIA, PL. 34. FIG. 23. 



V. testa longitudinali, oblique triangulari, sub-intequilaterali, postice et antice sub-angulatd, compressd, crassd. striatd; striis 

 concentricis raris; margine basalt minime curvato; margine dorsali angulato; natibus prominentibus, acutis; dentibus tribus 

 divergentibus; cicatrice palleali acute sinuata; lunuld magnd, elevatd, lined impressd marginatd. 



Shell longitudinal, obliquely triangular, sub-inequilateral, somewhat angular posteriorly and anteriorly, compressed, 

 thick, striate ; striae concentric, few; basal margin slightly curved ; dorsal margin angular ; beaks prominent, acute; 

 teeth three, diverging; palleal impression acutely sinuate; lunule large, elevated, margined with an impressed line. 



Diam. .15. Length .30. Breadth .31 of an inch. 



Remarks. The surface is somewhat rugulose with irregular lines of growth, which, 

 in two or three places, amount almost to ribs. The general outline is that of a triangle 

 with slightly curved sides. 



This shell has an unusual shape for a Venus, but the three distinct cardinal teeth will 

 not admit it into any other genus. Although the sinus of the palleal impression is deep 

 and acute, it has not the circular outline of the Artemis. 



FAMILY 



GENUS HIATELLA. 

 H. LANCEA, PL. 34. FIG. 24. 



H. testa transversissimd, in<zquilaterali, postiee et antice truncato rotundatd, minime hiante, valde compressd, concentricc 

 striata; striis minimis; clivo umboniali elevato; margine basali recto; margine dorsali medio sub angulato, postice et antice recto; 

 natibus prominentibus; dentibus magnis. 



Shell very transverse, inequilateral, truncately rounded posteriorly and anteriorly, gaping very slightly, very much 

 compressed, concentrically striate; strise very small; umbonial slope elevated; basal margin straight; dorsal margin 

 stVb-anguiar in the middle, straight posteriorly and anteriorly; beaks prominent; teeth large. 



Diam. 10. Length .15. Breadth .29 of an inch. 



Remarks. The lines of growth are very small and inconspicuous. The two teeth in 

 the left valve diverge considerably. The anterior one is bifid. 



This genus is placed in the family CardiidaB by Lamarck, and in the Lithophagidas by 

 Sowerby, who does not regard it as distinct from Saxicava. Which is right, I have no 

 means of determining, and I therefore leave it where Lamarck places it. 



FAMILY 



GENUS NUCULA. 



N. DOLABELLA, PL. 34. FIG. 25. 



N. testa oblique triangulari, inaquilaterali, postice et antice angulatd, inflata, crassiusculd, striatd; striis concentricis, 

 minutissimis; striis longitudinalibus, pene obsoletis, raris, clivo umboniali precipiti; margine basali curvato; margine dorsali 

 media acute angulato, postice et antice recto: dentibus parvis; cochlea parvd, sub triangulari; margine interno cremilato. 



