2 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 20 



In an appendix is a list of all samples in the collection, arranged from 

 north to south. The list of references is not intended to constitute a com- 

 plete list of literature for this region but gives only those titles to which 

 reference has been made. 



Science will always be indebted to Captain Allan Hancock, whose 

 interest in marine research has made the accumulation of this rich material 

 possible. 



Personally I wish to give my heartiest thanks to Captain Allan Han- 

 cock and to the Research Committee of the Allan Hancock Foundation 

 for giving me the opportunity to work on this material as a Research 

 Associate of the Foundation. I also wish to express my warmest thanks 

 to Dr. Norman T. Mattox, who has helped me in many ways and who 

 has taken the trouble to read the manuscript and correct the language. 

 I am especially indebted to Mrs. Dorothy M. Halmos, librarian of the 

 Hancock Library, who has brought the manuscript to a form correspond- 

 ing to the other papers in this series, checked the names and references, 

 and smoothed out the language. The drawings accompanying this paper 

 have been carefully executed by the staff artist, Mr. Gaylen C. Hansen, 

 who has shown a great interest in this difficult and time consuming work, 

 for which I am very thankful. The photographs for the plates have been 

 made by the stafiF photographer, Mr. Roy V. George. 



I am indebted to many scientists for the use of collections in their care, 

 for comparison and for loan of specimens, some of which are reproduced 

 in the plates, and I wish here to express my gratitude to Dr. William 

 J. Clench, Museum of Comparative Zoology, Cambridge, Mass. ; Dr. 

 Harald A. Rehder, U. S. National Museum, Washington, D. C. ; Dr. 

 Leo G. Hertlein, California Academy of Sciences, San Francisco; Dr. A. 

 Myra Keen, Stanford University, Palo Alto; Dr. S. Stillman Berry, 

 Redlands; Dr. Heinz A. Lowenstam, California Institute of Technology, 

 Pasadena; Dr. Howard Hill, Los Angeles County Museum, Los An- 

 geles; Mr. E. P. Chace, San Diego Museum of Natural History; Mr. 

 John Q. Burch, Los Angeles; and I am especially indebted to Mr. John 

 E. Fitch, California Department of Fish and Game, San Pedro, for 

 bringing me many living specimens or specimens preserved in alcohol, 

 for study. 



