121 



1659 Ancylus rivularis Say. 



Shell delicate, moderately elevated; sides slightly convex, 

 diverging anteriorly; posterior and dextral slopes concave, an- 

 terior slope convex, and sinistral one nearly rectilinear; apex 

 subacute, projecting, l-3d of the shell posterior to it. Color light 

 brown; nacre, in large individuals, white. Lon. 5, lat. 3.5. elev. 

 2mm. 



Delaware and Susquehanna rivers. — Montana (Squyer). 



1660 Anodonta ovata Lea. 



1661 Anodonta plana Lea. 



Squyer records these two from Montana. 



1662 Doridium Adelhe Dall. 



"Animal naked, about 16 mm. long, of a dark plum color, 

 mottled with fine vermiculate spots of golden yellow; general 

 form that of D. carnosum Cuvier, but with a shorter velum, half 

 as long as the body and transversely truncate behind; the poste- 

 rior portion of mantle short, obscurely bilobed, and without a 

 flagellum; front edge of the velum slightly excavated; parapodia 

 wide, the sole slightly longer than the body; shell internal, sub- 

 conical, white covered with a brownish epidermis; pillar strong, 

 reflected with a deep groove outside of it, the basal end project- 

 ing spur-like; nucleus small, depressed." — Dall, Nautilus 8:73. 



Type locality: — Eagle Harbor, Puget Sound, in 30 fms. (Miss 

 Adella M. Parker). 



1663 Genus Epiphragmophora Doering 1875. 



Pilsbry (Nautilus 8:81) states this is the earliest name used 

 for Arionta, Aglaia and Euparypha of American writers. 



1664 Epiph. ellipsostoma Pilsbry, Nautilus 8:81. 



Type locality: — "San Juan del Norte" (Gabb), probably on the 

 east coast of Lower California. 



1665 Lepidopleurus percrassus 



"Shell solid, strong, small, of a pale pinkish-brown with a 

 darker brownish girdle which appears rather narrow in the dry 

 state; scales very minute, partly dehiscent, chaffy, with occasional 

 slender spinules resembling hairs; scales on the base crowded, 

 minute, sandy; an extension of girdle is prolonged between the 

 valves on each side as far as the jugum, the surface of these 

 sinuses is also minutely scaly with occasional spinules; valves 

 thick, white below, moderately arched with the prominent jugum 

 forming a sort of keel; near the points of insertion the valves 

 are heavily callous below; the sutural laminae are short, smooth 

 and separated at the median sinus by a prolongation of the jugum 

 in advance of the anterior margins of the pleurae; sculpture of 

 the jugum consisting of punctate fore-and-aft parallel grooves 

 with some small elevated transverse ridges anteriorly; the rest 

 of the valve has, on each side, 6 or 8 vermicular ridges divari- 

 cating toward tne posterior edge of the valve and irregularly cor- 

 rugated with sharp, fine, elevated lamellae crossing the inter- 

 spaces transversely but fading out on the ridges; head-valve with 

 minutely nodulous concentric ridges; tail-valve highest at the 

 subcentral, not very prominent mucro, in front sculptured like 

 the intermediate valves, behind the mucro like the head-valve. 

 Length about 14, width 5.75, height 2.5 mm., in the dry state. 

 The dry girdle about 0.5 mm. wide." — Dall, Nautilus 8:90. 



