86 THE NAUTILUS. 
A number of valves collected near the head of the Gulf of Cala. 
by Dr. E. Palmer some years ago. 
Pecten Randolphi Dall, n. sp. 
Shell small, thin, glassy, unsculptured, except by minute “ camp- 
tonectes ” striation which covers both valves, and more or less ob- 
scure concentric undulations which are most distinct on the right 
valve near the umbo, and in some specimens altogether absent ; 
hinge straight and short, anterior ears distinct, posterior ears not 
defined by any fold or sinus, outline suborbicular, valves com- 
pressed, especially the right one; right anterior ear with six small 
imbricated radii above, below a wide, transversely striated fasciole 
derived from a well marked byssal sinus ; ctenolium with four or five 
functional spines. Alt. 27-5, lat. 26, diam. 5 mm, 
Off Destruction Island, State of Washington, in 516 fathoms, 
bottom temperature, 38° Fahr., U.S. Fish Commission. 
This species was obtained at a number of stations, from Bering 
Sea to West Mexico, in 225 to 1005 fathoms. It is named in honor 
of Mr. P. B. Randolph, of Seattle, who has done excellent work on 
the Puget Sound fauna. 
Pecten Davidsoni Dall, n. sp. 
Shell small, suborbicular, compressed, waxen white, the left valve 
with 21 rounded ribs, surmounted by (when not worn off) continu- 
ous rows of minute subglobular scales, the interspaces wider, flat and 
perfectly smooth, ears very small, the anterior with five or six im- 
bricated radii; sculpture obsolete near the umbones; right valve 
sculptured with faint concentric impressed lines over the whole sur- 
face, and distally with numerous minute, obsolete, fine, scaly riblets ; 
posterior ear transversely striated, very small, anterior one with four 
or five scaly radii, a well marked sinus leaving an imbricated fas- 
ciole and no ctenolium. Interior polished, the left valve fluted 
internally in harmony with the external ribs. Alt. 14, lat. 14, 
diam. 3°D mm. 
On the Davidson Bank, Alaska, in 280 fathoms, green mud, and 
north of Unalashka, in Bering Sea, in 351 fathoms, sand; U.S. 
Fish Commission. 
This little shell resembles somewhat P. (Propeamusium) alasken- 
sis Dall, externally, but wants the radiating lire internally, is 
smaller, and has faint radiating sculpture on the right valve, which 
is wanting in P. alaskensis. 
