CHAMIDAE 393 



of the valves. The paUial Hne runs directly to the anterior muscle scar and 

 not past the end as in the other species. This is a reef species. An ecological 

 variety of heavy shell has been named fir7na Pilsbry and McGinty 1938. 



Chama pellucida Broderip Clear Jevv^el Box 



Plate 37a 



Oregon to Chile. 



I /4 to 3 inches in size, with frond-like, smoothish foliations. Color 

 opaque to translucent-white. Interior chalk-white, the margins minutely 

 toothed or crenulate. Commonly found attached to pilings, breakwaters and 

 floating wood. Also dredged down to 25 fathoms. 



Genus Pseiidochama Odhner 191 7 



These are mirror images of the chamas. According to Odhner, the anat- 

 omy and prodissoconchs differ in the two genera. 



Fseudocha77ia radia?js Lamarck Atlantic Left-handed Jewel Box 



Plate 37c; figure 79c 



Southern Florida and the West Indies. 



I to 3 inches in size. This is the only species of Fsendochama in eastern 

 America. It is not very colorful, and ranges from a dull-white to a dull 

 purplish red. The interior is commonly stained with mahogany-brown. 

 Crenulations are present on the inner edges of the valves. In shape, it is a 

 mirror image of simwsa. P. ferriiginea Reeve is considered a synonym. 

 Common. 



Pseudo chama exogyra Conrad Pacific Left-handed Jewel Box 



Oregon to Panama. 



Similar to pellucida, but attached by the right valve which, when viewed 

 from the inside, is arched counterclockwise. The opaque whitish area inside 

 is generally not bordered by tiny crenulations. A common intertidal species. 



Pseudochavia echinata Broderip in the Gulf of California is a popular 

 shell which is characterized by a watermelon-red hinge and purple-stained 

 interior. 



Pseudochama grajiti Strong (Grant's Chama), dredged off central Cali- 

 fornia and Catalina Island, is about i inch in size, with prickly spines on the 

 underside of the attached, cup-formed valve. One end of the valve is tinted 

 with rose inside and out. Not common. 



