Explanation of Plate 26 



Figs. 1-3. — Hiatella arciica (Linnaeus) from 10 feet (Sept. 8, 1949), showing variations in 

 anterior and posterior ends. (The elongate form most common at Point Barrow.) 



Fig. 4. — Clinocardiuni cilialum (Fabricius) from 110 feet (Sept. 8, 1948). 



Fig. 5. — Serripes gronlandica (Bruguiere) from 40 feet (Eluitkak Pass). 



Figs. 6-9. — Macoma calcarea (Gmelin): 6-8, from 132 feet; 9, from 118 feet, showing 

 variation in shape of anterior end and in proportion of height to length. 



Magnification: All X 1-9. 



