40 WEST AMERICAN SHELLS 
slender 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 Pécten hericeus, Gld., the Pink Pecten. 
In West Coast Shells it was named Pécten has- 
tatus, 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 of 
the shell are very vivid, ranging through various 
tints of red, yellow, and purple. 
Pécten rubidus, Hds., the Red Pecten, is from the 
north, and closely resembles Figure 19, but the 
ribs are more smooth and even, and are without 
the serrations so prominently seen in that species. 
Peécten latiauritus, Conr., the Broad-eared Pec- 
ten, is a southern species, about an inch across, 
having thin valves, with twelve to fifteen squarish 
distinct ribs. The ears of the shell, by which we 
mean the flattened parts on each side of the umbo, 
are broad and pointed. Color, white and brown. 
A variety of this species, known 
as var. monotimeris, Conr., is shown 
in Figure 20. In West Coast Shells gy 
it was described as a distinct species. { 
The shell is very thin and delicate, 
the ribs rounded and rather faint, 
and the ears are smaller than in the 
last. The colors incline to yellow and brown, vari- 
