NO. 1 



SOOT-RYEN : THE FAMILY MYTILIDAE 



21 



Fig. 1. Mytilus edulis Linne. Yaquina Bay, Oregon. Common 

 thick-shelled form. 



Fig. 2. Mytilus edulis Linne. Mission Bay, San Diego. High, thin- 

 shelled form with small anterior adductor {diegensis Coe). 



Fig. 3. Mytilus calif ornianus Conrad. San Pedro. Note the place- 

 ment of the anterior adductor. 



Fig. 4. Choromytilus falliopunctatus (Carpenter). Salina Cruz, 

 Oaxaca, Mexico. Anterior retractor placed behind the 

 middle of the ligament; no anterior adductor. 



