150 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 8 



429-35. Octavia Bay, Colombia, north end of channel, coarse sand and 



gravel, 35-40 fms., January 27, 1935, 1 specimen, young. 

 431-35. North of Octavia Bay, Colombia, south end of channel, 45 



fms., January 27, 1935, 1 specimen. 

 529-36. Off San Francisquito Bay, Gulf of Calif., shale and gray mud, 



165 fms., March 1, 1936, 1 specimen. 

 780-38. Chatham Bay, Cocos Island, Costa Rica, 40-47 fms., January 



14, 1938, 3 specimens. 

 792-38. Off Daphne Minor Island, Galapagos, 70-80 fms., January 20, 



1938, 1 specimen. 

 854-38. North of Gorgona Island, Colombia, 40-60 fms., February 24, 



1938, 1 specimen, young. 

 Remarks. — The species is very striking and cannot be mistaken for 

 any other Pacific form, except the closely related P. macrolepis Fisher 

 from Hawaii, 154 fms. depth. The latter has almost smooth plates in the 

 sole and small basal scales intercalated between the oral valves. The 

 depth, 7-10 fms., for the specimens from La Plata Island, is unusually low 

 for this species and may indicate that peculiar hydrographic conditions 

 prevail in that locality. 



