Zostera marina in Alaska — McRoy 
513 
U.S. Fish and Wildlife Service, North Ameri- 
can Fauna, No. 61, 406 pp. 
Palmer, L. J. 1941. Unpublished field notes. 
Univ. Alaska Archives. 
Polunin, N. 1940. Botany of the Canadian 
Eastern Arctic. Part I. Pteridophyta and Sper- 
matophyta. Natl. Museum Canada, Bull. 92, 
408 pp. 
Porsild, A. E. 1932. Notes on the occurrence 
of Zostera and Zannichella in arctic North 
America. Rhodora 34(401) : 90-94. 
Sculthorpe, C. D. 1967. The Biology of 
Aquatic Vascular Plants. St. Martins Press, 
New York. 610 pp. 
Setchell, W. A. 1920. Geographical distribu- 
tion of the marine spermatophytes. Bull. 
Torrey Bot. Club 47(12) :563-579. 
1935. Geographic elements of the 
marine flora of the North Pacific Ocean. Am. 
Naturalist 69(725) :560-577. 
Steinbeck, J., and E. Ricketts. 1941. Sea of 
Cortez. Viking Press, New York. 598 pp. 
Von Arx, W. S. 1962. An Introduction to 
Physical Oceanography. Addison- Wesley 
Publ. Co., Reading. 422 pp. 
Zenkevitch, L. A. 1963. Biology of the Seas 
of the USSR. Interscience Publ., New York. 
955 pp. 
