4 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 14 



many species are found through the whole area that no line of separation 

 can be drawn. The more northern species tend to disappear south of 

 Vancouver Island and the more southern ones at the same point, but 

 Puget Sound and southern British Columbia show a great mixture, with 

 even a few warm water species present. In spite of the latitude, there is 

 cool water along the California coast, with occasional inlets where the 

 temperature is somewhat higher. 



3. A more temperate area extends from Point Conception and the 

 northern Channel Islands off southern California to Cedros Island and 

 Point Eugenia, half way down the peninsula of Lower California (27° 

 30' N Lat.). In addition to numerous species characteristic of moderate 

 temperature there is a great mixture, with some of the more northern 

 species reaching their limit among the Channel Islands and an increasing 

 number of tropical species south of the Mexican boundary. 



4. The truly tropical area extends from Cedros Island and the same 

 latitude (27° 30') in the Gulf of California to the vicinity of San Juan 

 Bay, Peru (15° 20' S Lat,). Throughout this wide area there is much 

 similarity in the bryozoan fauna and the great majority of the species are 

 limited to tropical waters. Moreover, most of the species are found widely 

 distributed along this coast and about the outlying islands (Socorro, 

 Clarion and the Galapagos). No doubt there are endemic species which 

 are limited to a narrow range, but it would be hazardous to predict this 

 in any case, as continued dredging may recover them in unexpected areas. 

 Species hitherto known only from the Galapagos Islands have been taken 

 by the Allan Hancock Expeditions at various places along the mainland, 

 even as far north as the coast of Mexico and the Gulf of California. 



Acknowledgments 



To Captain Allan Hancock, Director of the Allan Hancock Founda- 

 tion, who through financial assistance has made possible this extended 

 research, I owe a deep debt of gratitude. To Dr. Irene McCulloch of the 

 Foundation, who has placed many facilities for work at my disposal and 

 whose interest in the progress of the work has been an inspiration, I am 

 also deeply thankful. Dr. Arthur D. Howard, Mr. John D, Soule, and 

 Miss Mary G. Marsh have relieved me of much tedious sorting of ma- 

 terial. I must here also record the valuable assistance of my friends, Dr. 

 R. S. Bassler of the U. S. National Museum and Dr. Anna B. Hastings 

 of the British Museum of Natural History; Dr. Bassler has given me 

 access to valuable type material, Dr. Hastings has made numerous com- 

 parisons for me, and both have presented me with specimens important for 

 this study. 



