The Scallops. Comb Shells 



The Speckled Scallop (P. cEqidsulcatus, Cpr.) has the 

 symmetry of form, the even fluting and the various colouring 

 and markings of the scallops of our warmer Atlantic coasts. 

 Its scheme of colours leans toward shades of brown. Diameter, 

 2 to 3 inches. 



Habitat. — Southern California. 



P. Diegoensis, Dall, has a dark red, flattened upper valve, 

 with twenty distinct ribs. The lower valve is yellow. Diam- 

 eter, 3 to 5 inches. 



Habitat. — San Diego, Cal., northward. 



This large scallop has a companion in the Californian cap 

 shell {Capulus Californicus, Dall) which clings to the under 

 valve, at the left of the hinge, close to the byssal notch. White 

 within, dingy brown and shaggy without, it may well be mis- 

 taken for a wad of dead seaweed clinging to the larger shell. 

 It is about an inch and a half long. 



P. distorsum, Da C, attaches itself inside the shell of another 

 species. The under valve of the parasite becomes imbedded in 

 the lining of its host's shell. We can imagine this arrangement 

 involves much discomfort for both partners, as growth proceeds. 



The Spear Scallop (P. hastatus, Sby.) is ovate, with comb- 

 like rows of spines on each of the ten most prominent ribs. These 

 are worn off of the right valve. The colours are vivid; red, pur- 

 ple and yellow in different shades are seen. Free-swimming 

 forms, alike on both valves, and spineless, are local forms. The 

 young are spineless. 



The animal alive in an aquarium shows not only the beauty 

 of its rosy shell set with rows of spears. The body is a rich orange 

 colour, set on the mantle margin with black eyes. The flesh 

 is so transparent that the action of the heart and other organs 

 can be seen by removing one valve. Young specimens can 

 attach themselves at will to the stems of seaweed. Thus they 

 rest when tired of swimming. 



This deep sea species seems to correspond in its characters 

 to P. Islandicus. Diameu .r, i to 2 inches. 



Habitat. — California. 



The Broad-eared Scallop {P. lati-auratus, Conr.) has un- 

 equal ears almost as broad as the fragile, oblique, fluted shell. 

 The brown or orange surface is crossed by zigzag streaks of white. 

 Diameter, i inch. Southern California. 



