' Descriptions of New Species of Ancylus and Anculosa. 159 



recurved, sub-central; anterior and posterior slopes, convex; 

 lateral slopes, plane ; apicial region rose-colored. 



Habitat. — Green River, Kentucky ; adhering to small stones 

 and dead shells. Very rare. 



My Cab. Cab. Lyceum, N. Y. 



Length, 0.26 inch (6^ mill.) ; breadth, 0.21 inch (5 mill.) ; 

 height, 0.14 inch (3| mill.) 



Obs. — This is rather a heavy, robust species, and one not easily 

 confounded with any other ; it most nearly resembles, perhaps, 

 Ancylus crassus Hald., but differs from it in being more 

 elevated, in having the lines of growth coarser, and by its rosy 

 apex. It is more elevated than any other specimens of the 

 genus with which I am acquainted. 



It is somewhat singular that this should have been the only 

 species of Ancylus noticed in a journey of nearly 1,800 miles, 

 during which every stream was examined for shells, and this 

 genus was anxiously sought for. 



Aracselosa ampla. 



Plate V. Fig. 22-23. 



T. ovato-globosa, glabra, virente, purpureo-fusco quadrifasciata ; spira, 

 brevi, erosa; anfr. 2-3, ultimo lnuneroso, tuberculis perpaucis prope 

 suturam vix perspicuis ; sutura profunda; apertura ovata, intus purpureo- 

 faseiata ; columella excavata, planata, fusca. 



Shell ovate-globose, olive-green, with four dark-colored bands ; 

 spire very short, eroded ; whorls 2-3, the last one shouldered, 

 and peculiarly flattened just before completion, and having the 

 shoulder raised into a few very slightly defined tubercles, which 

 in some individuals are hardly perceptible ; suture deeply exca- 

 vated ; aperture ovate, showing the dark bands of the exterior ; 

 columella brown, excavated and flattened, without basal sinus, 

 giving that portion of the shell much resemblance to a Littorina. 



Length, 0.62 inch (16 mill); diameter, 0.42 inch (11 mill.); 



