ExpLAXATiox OF Plate 22 



Figs. 1-6. — Astarte horealis Schumacher, showing variations in shapes of anterior and 

 posterior ends, in the ventral Hne, in sculpture, and in the proportion of height to 

 length: 1, 2, from 40 feet (Eluitkak Pass, Aug. 10, 1948); 3-5, from 120 feet (Aug. 8, 

 1949); 6, from 40 feet (Eluitkak Pass, Aug. 1, 1950). 



Figs. 7-10. — Cardita crassidens (Broderip and Sowerby): 7, a high form from 110 feet 

 (Sept. 8, 1948); 8, an intermediate form from 130 feet (Aug. 9, 1949); 9, an elongate 

 form (= forma paucicostata), from same haul; 10, a specimen that grew in cramped 

 quarters, producing a boxlike shape, from same haul. 



Figs. 11-16. — Astarte montagui (Dillwyn) vars.: 11, var. zcarhami Hancock, a typical var. 

 zvarhami, from 204 feet; 12, a younger, lighter colored var. zvarhami from 125 feet; 13, 

 a young, light colored specimen from 40 feet (Eluitkak Pass); 14-16, var. striata Leach 

 from 118 feet. 



Magnification: All X .83. 



