MUSSELS AND PECTENS 



41 



Fig. 20 



unequal, and the 

 edges of the principal 

 ribs are cut into 

 many short and slen- 

 der teeth. The valves 

 differ from each other 

 in sculpturing and 

 color, the under one 

 having more ribs and 

 being nearly white, 

 while the upper one 

 is richly marked with 

 concentric bands of 

 pink. Its name is Pecten hericeus, Gld., the Pink 

 Pecten. 



It has sometimes been mistaken for Pecten liasta- 

 tus, Sby., the Spear Pecten. That name is now 

 applied to a similar species, closely allied, found in 

 deep water off Southern California, the adult shells 

 of which are about one and a half inches across. 

 The ten very prominent ribs on the back have long- 

 toothed combs, while the colors are very vivid, 

 ranging through various tints of red, yellow and 

 purple. 



Pecten ruhidus^ Hinds, the Red Pecten, is from 

 the north, and closely resembles the shell shown in 

 Figure 20, but the ribs are more smooth and even, 

 and are without the serrations so prominently seen 

 in that species. 



Pecten latiauritus^ Conrad, the Broad-eared Pec- 

 ten, is a southern species, about an inch across, hav- 

 ing thin valves, with twelve to fifteen squarish. 



