151 
2188 Psephidia Lordi 
Synonymy:—Chione Lordi Baird, 1863.—Psephis Lordi ea 
Port Etches, Alaska.—Catalina Island, Cal., in 4-15 fms. 
White, pale green or straw color, quite trigonal and plump, 
often containing the nepionic young. 
2189 Psephidia ovalis 
“Shell small, white, polished, oval, subcompressed; surface 
with obsolete concentric threads near the anterior base, but over 
most of the disk smooth; beaks small and very low, at about the 
anterior third of the length; lunule elongated, extremely narrow, 
nearly as long as the anterior dorsal slope; escutcheon linear or 
none; interior white, the pallial sinus moderate, pointed; inter- 
nal margin delicately striated; hinge well developed, like that of 
P. Lordi, with 3 entire cardinals and no anterior lateral tooth. 
Length 8.5, height 6.5, diam. 3 mm.’’—Dall, U. S. Natl. mus pr 
26:407. 
Type locality:—north side of Catalina Island, Cal., in 16 fms. 
—Bering Sea to San Diego, Cal., in 3-20 fms. 
2180 Gemma gemma Totten, 1834. 
Variety purpurea H. C. Lea. 1842. 
Cape Cod to the Bahamas.—Texas.—San Francisco, Cal., in- 
troduced with oysters about 1899. 
More inflated than typical form, trigonal, and with uniform 
concentric threads sharply defined; color variable. 
Synonymy:—G: concentrica Dall. 1889. 
—__—__- 9 —_——___— 
2191 Dall, William Healey: 
Synopsis of the family Astartide, with a review of the Amer- 
ican species. U.S. nat mus pr 26:933-951, t 62-63. 
Nos. 2192-2201 are species not already listed. 
2192 Astarte alaskensis 
‘Shell ovate, subcompressed, white, with a dark, strong, cadu- 
cous periostracum, which, like that of A. elliptica, becomes black 
in the dead or senile shells; valves quite inzquilateral, beaks at 
the anterior third, elevated, slight compressed, prosagyrate; lu- 
nule excavated, sublanceolate, the escutcheon longer and wider;. 
sculpture of about a dozen concentric riblets with wider inter- 
spaces, more feeble near the ventral and posterior margins; inner 
margins entire, smooth; hinge solid, the teeth narrow and entire. 
Height 26, length 31.5, diam. 14 mm.’’—Dall, t 63 f 2. 
Type locality: Unimak Island, in 70 fms. 
2193 Astart polaris 
“Shell rounded-trigonal, moderately thick, bluish white, cov- 
ered with a slightly polished light-brown periostracum; valves 
moderately convex, with the umbones high, somewhat prosogy- 
rate, over a well-impressed lanceolate lunule, which is unequally 
divided, the right valve bearing the larger share; escutcheon nar- 
rower and longer than the lunule, impressed, smooth; sculpture of 
40 or more small, narrow, regular, concentric riblets separated by 
about equal interspaces; in the adult the posterior slope and ven- 
tral 3d of the disk have the riblets replaced by somewhat uneven 
concentric striation; interior smooth, the inner margins finely 
evenly crenate; hinge rather solid, the middle cardinal in each 
valve grooved or bifid. Height 25, length 28, diam. 15 mm. 7 
Dall, t 63 f 5. gia 
Type locality: —Shumagin Islands, Alaska, in 51 fms. Also: 
Greenland. 
