UNITED STATES DEPARTMENT OF THE INTERIOR, Stewart L. Udall, Secretary 

 FISH AND WILDLIFE SERVICE, Arnle J. Suomela, Commissioner 

 Bureau of Commercial Fisheries, Donald L. McKernan, Director 



EMBRYOLOGICAL STAGES IN THE SEA 



LAMPREY AND EFFECTS OF TEMPERATURE 



ON DEVELOPMENT 



By George W. Piavis 



FISHERY BULLETIN 182 



From Fishery Bulletin of the Fish and Wildlife Service 



VOLUME 61 



Published by the U.S. Fish and Wildlife Serrlce • Washington • 1961 

 Printed at the U.S. Govemment Printing Office, Washington, D.C. 



For sale by the Superintendent of I>ocuments, U.S. Government Printing Office 

 Washington 25, D.C. - Price 30 cents 



