204 
site valve in closing; beaks opisthocelous, inconspicuous. Height, 
24; length, 39; diameter, 20 mm.’’ 
Type locality:—off the Californian coast in deep water. 
3075 Psephidia cymata 
“Shell small, white, solid, rounded triangular, with inconspic- 
uous, somewhat anterior beaks, the lunule and escutcheon very 
feebly indicated; surface with fine concentric but not perfectly 
regular low threadlike sculpture; periostracum yellowish, rather 
coarse; hinge of the genus, inner margins smooth, interior disk 
polished, the pallial sinus small, ascending, the inner extreme 
bluntly rounded; muscular impressions distinct, ligament small 
and weak. Height, 5.5; length 6.0; diameter 2.5 mm.”’ 
Type locality:—near Cerros Island, Lower Cal., in shallow 
water. 
3076 Lyonsia (Allogramma) Amabilis 
‘Shell thin, with a pale olivaceous periostracum and pearly 
interior, the lithodesma small. The sculpture resembles closely 
that of the type of the group, L. (A.) formosa Jeffreys, from the 
Canaries, but differs in the following details; the anterior trans- 
verse ripples, the central nodulous ray, the radial ridge below the 
posterior dorsal area are more vertically directed; on the latter 
area there is only faint indication of the radial ribbing which in 
L. formosa is distinct and minutely spinose; the anterior end is 
longer than the posterior, while in formosa the reverse is the case; 
the coloration of the periostracum is olivaceous green while in 
formosa it is ferruginous brown. Length 23; of anterior end 12; 
height 15; diameter 12 mm.”’ 
Type locality: —Santa Barbara Channel, Calif., in deep water. 
3077 Lyonsia pugetensis 
‘Shell large, thin, pearly under a thin olivaceous gray perios- 
tracum which is covered with fine radial lines to which fine sand 
adheres strongly, so that an attempt to remove the sand also de- 
stroys the greater part of the periostracum; the shell is slightly 
inequivalve and very inequilateral, the anterior end being much 
shorter; the periostracum projects over the shelly margin; the an- 
terior end is evenly rounded, the posterior rostrate, the beaks not 
conspicuous; the base is convexly arcuate in the middle but is 
rapidly attenuated toward the rostrum, which is terminally trun- 
cated; interior pearly, pallial area relatively small within the 
somewhat irregular unsinuated pallial line; hinge edentulous 
with a small narrow lithodesma. Length of shell 36; of anterior 
portion 15; height at beaks 17; maximum diameter 10 mm.”’ 
Type locality:—coast of Washington. 
3078 Poromya (Dermatomya) Tenuiconcha 
“Shell small, thin, olivaceous, the pearly luster showing 
through the periostracum; equivalve, inequilateral, anterior end 
shorter, rounded in front; posterior end longer, roundly truncate; 
beaks prominent, prosocclous, with a marked but uncircum- 
scribed depression in the lunular region in front of them; interior 
pearly, brilliant; margins simple, sharp; hinge in the left valve 
with a small internal resilium seated on an inconspicuous oblique 
chondrophore, with a notch immediately in front of it, into which 
fits a projecting denticle on the corresponding part of the oppo- 
site valve. Height, 13; length of shell, 16; of anterior portion, 
6; diameter, 10 mm.”’ 
Type locality: —-Off Monterey Bay, California, in deep water. 
