78 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 23 



Pecten (Pecten) islandicus Miiller variety hindsii Carpenter. Grant & 

 Gale, 1931, p. 163. Previous Pliocene, Pleistocene and Recent 

 records. 

 Chla/nys Hindsi \sic^ Carpenter. Bavay, 1936, p. 310. 

 Pecten (Chlarnys) hindsii hindsii Carpenter. Proc. Conch. Club So. 

 Calif., 1944, no. 35, p. 6. "The source of the San Pedro and San 

 Diego records . . . open to question." 

 Chlarnys islandica hindsi [sic\ (Carpenter). Kuroda & Habe, 1952, p. 

 16. Pacific: 42° N - 55° N. Kira, 1955, p. 49, pi. 49, fig. 9. Hok- 

 kaido, Japan; 100 fathoms. 

 Chlarnys hindsi {sic\ Dall {^'T)?i\V' lapsus calarni for Carpenter]. Abbott, 

 1954, p. 365, pi. 34, fig. 1. "Alaska to off San Diego, California." 

 ". . . dredged . . . down to 822 [typ. err?] fathoms." 

 Pecten (Chlainys) rubidus Hinds. Palmer, 1958, p. 69, pi. 3, figs. 4-6. 

 Holotype: ? No longer in British Museum. 

 Type locality : "Alashka." 



Original description : Testa subtrigono-orbiculari, inaequaliter duplo- 

 convexa, inaequiauriculata subtenui ; valva sinistra convexa, costis parvis 

 numerosissimis, serratis, in fasciculos duarum triumve alternate aggre- 

 gatis, rufis, interstitiis pallescentibus ; valva dextra subconvexa, al- 

 bida, costis majusculis, aggregatis; auriculis sulcatis, postica parva, 

 obliqua ; intus, alba. 



Additional description: Adult specimens averaging 50 millimeters 

 in height and slightly higher than long ; left valve more convex than 

 right, and hinge line about half length of disk. Right valve vv^ith extreme- 

 ly variable rib structure; 21 to 28 low, smooth, broad and rather flat 

 primary ribs, becoming dichotomous at about 10 to 15 mm from hinge 

 line and occasionally imbricated near ventral margin; ribs frequently 

 narrower, obscurely fasciculated and almost entirely imbricated. Riblets 

 often develop in interspaces, usually starting at 15 to 20 mm from hinge 

 margin and occasionally imbricated. Interspaces narrower than ribs and 

 with minute reticulations present in either upper or lower portion or 

 throughout. Anterior auricle large and with 6 or 7 riblets having fine 

 concentric imbrications ; byssal notch prominent, and ctenolium of 5 to 7 

 teeth. Posterior auricle small, with 8 to 11 small spinose riblets; hinge 

 margin tapering gently downward from beak. Left valve also variable in 

 rib structure; primary ribs simple at first, later fasciculated; each fas- 

 cicle consisting of three (occasionally two) imbricated ridges, often worn 

 smooth at maturity; imbricated secondary rib usually present in center 

 of each interspace, often flanked by two very small rows of spines. Inter- 

 spaces wider than ribs and minutely reticulated from umbo to center of 



