beet 
4 eye 
a. * R aane “ay, 
i ane % é ha 
Cen . Aap 
- he, 
s 
“a a 3 . “ 
—< 4 J LS oe 7 ee SK 
oe SN EN Ae IER Le TORRE 8 = i Sa. lat oat gy Ee , 
PTE ee ee , TORTS, 12 pe! a+" rts, ~™ Satin ‘ 
centrically lamellose; anterior ear with 5 radial lines, coarsely 
lamellose with a shallow notch and serrate margin. Height 14, 
breadth 15, diameter 3 mm, Off San Diego, Cal., 684 fathoms. 
21:0082 Pecten (Pseudamusium) bistriatum Dall. 
Shell small, suborbicular, moderately convex, white, thin; 
left valve finely concentrically, rather distantly lamellose, the 
lamellae closer and more conspicuous on the subequal ears; 
radial sculpture of very fine, close-set, uniform almost microscopic 
elevated lines, which do not reticulate the lamellations; right 
valve with the concentric, but without the radial sculpture, con- 
cave near margin, the disk about as convex as the other valve, 
ears subequal, byssal notch short, acute; 1 or 2 faint radii on — 
ear above it; height 7, breadth 7, diameter 2 mm. Off San Diego, 
Cal, 822 fathoms. 
21:0083 Limatula attenuata Dall. Atka Island. 
21:0084 Septifer bifurcatus obsoletus Dall. San Diego, Cal. 
Shell large, external sulpture ocbsolete. distal parts of valve 
nearly smooth. Mud flats, San Diego bay. 
21:0085 Modiolus (?politus Verrill var.) pallidulus Dall. 
Shell thin, smooth, brilliantly polished, attenuated anter- 
jlorly, wide and bluntly rounded behind, divided into 2 color areas, 
the dorsal large, translucent with a whitish zigzag reticulation, © 
the ventral opaque white with a yellowish tinge; hinge edentu- 
lous, margins entire; length 23, maximum height 11.5, beaks 
behind anterior end 1, diameter 5mm. Off San Luis Obispo bay, 
in 77 fathoms. 
21:0086 Dacrydium pacificum Dall. Bering Sea. 
21:0087 Musculus niger obsesus Dall. Bering Strait. Arctic 
Ocean to Cape Flattery. 
21:0088 Musculus niger protractus Dall. Nunivak Island, Ber- 
ing Sea, to Monterey, Cal, 
21:0089 Musculus olivaceus Dall. Off Bering Island (to Cata- 
lena Island, Cal.). 
21:0090 LITHOPHAGA Bolten, 1789. 
“The typical Lithophaga has a clean outer surface; section 
Diberus a divaricate plumose posterior incrustation; section 
Myoforceps, 2 crossed conical projections; section Labis has on 
each valve a semicylindrical smooth appendage of which the dis- 
tal end is internally flattened and somewhat separated from the 
appendage of the opposite valve, the ends being rounded.”—Dall. 
21:0091 Crenella rotundata Dall. Off Santa Cruz Island, Cal.,’ 
155 fathoms. 
Shell small, rounded-quadrate, inflated, with a very thin, 
dehiscent, pale olive periostracum; beaks central, inconspicuous, 
with no crenulations beneath them; sculpture of faint incremental 
lines and obsolete radial striae near*margin; inner margin very 
delicately crenulate except near the beaks; length 4, breadth 4, 
diameter 2 mm. 
