16 



few papers on the biology of commercial shrimp written under the Mexican 

 fisheries investigations, and a large number of papers on fisheries biology 

 and primary production by biologists working under the California 

 Cooperative Oceanic Fisheries Investigations and the Bureau of Commercial 

 Fisheries of the U.S. Fish and Wildlife Service. None of the above studies 

 has attempted an overall ecological analysis of the Gulf of California, 

 although many do discuss the zoogeographic divisions of the Gulf as 

 related to various floral and faunal groups. Two issues of Systematic 

 Zoology, published in 1960 (Garth, etal., 1960) were devoted to a sym- 

 posium on the zoogeography of the Gulf of California. 



Methods of Collecting and Analyzing the Data 



Collections of biological material for this study were made during the 

 period from November, 1958 through November, 1961 by a number of 

 expeditions. These expeditions were: "Tuna Oceanographic Cruise 

 11", November, 1958; "Vermilion Sea Expedition I", April-May, 

 1959; "Vermilion Sea Expedition 11", May-June, 1959; "Ver- 

 milion Sea Expedition-Shepard", April, 1959; "Southern Bor- 

 derland Cruise III", February, 1960; "Curray-Orca Cruise", 

 March-April, 1960; "Holt Expedition", December, 1960; "Baja 

 Slope Expedition", May, 1961; and "Curray-Gulf of California, 

 Winter Cruise", November, 1961, all made under the sponsorship of 

 Scripps Institution of Oceanography. Cruises "AEC-l", March, 1960, 

 "AEC-2", March-April, 1960, and "AEC-3", November, 1960, were 

 carried out by the Advanced Systems Development Division of Pneumo- 

 dynamics Corporation, El Segundo, California. 



Since none of these cruises was undertaken for the specific purpose of 

 benthic biological sampling, with the exception of the "Baja Slope" and 

 "Holt" expeditions (both in the Pacific on the west side of Baja Cali- 

 fornia), sampling was somewhat haphazard, depending entirely upon when 

 time was available for sampling the benthos. Most of these cruises were 

 primarily geological or geophysical in nature. No systematic program for 

 the collecting of quantitative grab or bio-mass samples could be carried 

 out, although a number of orange peel and small Van Veen samples were 

 taken on "Vermilion Sea Expedition I", and a few Petersen Grab 

 samples were taken by the author during "Vermilion Sea Expedition- 

 Shepard". All other samples were taken either with various dredges and 

 trawls or by diving and hand-collecting. Some conception of the principle 

 mode of sampling for each environment sampled can be gained from 



