COMPLETE GRAU : PECTINIDAE OF THE EASTERN PACIFIC 27 



SAN PEDRO BASIN (between southern California mainland and 

 Santa Catalina Island) : stations 1613-48, 2303-53, 2327-53, 2330- 



53, 2332-53, 2333-53, 2363-53, 2388-53, 2420-53, 2422-53, 2740- 



54, 2800-54, 2801-54, 400-495 fathoms. 



NORTHWEST OF SAN PEDRO BASIN: sta. 2964-54, 490 



fathoms; 3020-55, 445 fathoms. 

 WEST OF SANTA CATALINA ISLAND: sta. 2850-54, 620 



fathoms; 2970-54, 476 fathoms. 



Gyclopecten liriope (Dall) 1908 

 Plate 8, fig. 1 



Pecten (Pseudaniusium) liriope Dall, 1908, p. 402. 



Pecten (Delectopecten) liriope Dall. Hertlein, 1935, pi. 18, fig. 16. 



Photograph of holotype. 

 Pseudaniusium liriope Dall. M. Smith, 1944, p. 52. 



Holotype: U. S. National Museum. 



Type locality: Albatross station 3392, Gulf of Panama, in 1270 

 fathoms. 



Original description: Shell small, fragile, whitish, subcircular; con- 

 vex (left) valve with small subequal ears finely concentrically lamellose; 

 disk with extremely fine, close, rad^ial threads with nearly equal inter- 

 spaces; crossed by fine concentric lamellae, with wider interspaces, more 

 distant on the beaks, closer toward the margin; interior glassy, the 

 sculpture shining through; right valve similarly sculptured, except that 

 the radial threads are obsolescent and the concentric lamellae more 

 obvious; anterior ear longer with a wide byssal sulcus and fasciole, a 

 single radial thread bordering the fasciole; margin of the disk flexible. 

 Alt. 7.5 ; lat. 8.0 ; hinge line, 4.5 ; diam. 2.5 mm. 



A peculiar thing about the sculpture of this little shell is that, looked 

 at in one light, only the radial, in another only the concentric sculpture 

 is visible, and thus there is no effect of reticulation to speak of, yet there 

 is little difference in the strength of the two kinds of sculpture. 



Re?narks: Dall used the terms "white" or "whitish" in describing 

 several species which are, like this, actually transparent. Unless the 

 small deep-water shells of this family are separated and washed, thorough 

 study and accurate description are impossible. 



This species was previously recorded only from the type locality. 

 Dr. Harald A. Rehder sent the author some unidentified Albatross 



