2 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 1 1 



those years of study are presented herein in the form of a detailed taxo- 

 nomic report on the sponges of the Gulf of California, together with the 

 comparison of this fauna with that of the West Indies and of the coast 

 of California. 



ACKNOWLEDGME NTS 



The writer wishes to express sincere thanks to Dr. M. W. de Lauben- 

 fels, whose advice at all stages has been invaluable and whose generosity 

 with reprints, personal librarj^, and other material has been most helpful. 



Materials and Technique 



The sponges herein described were collected by members of the Allan 

 Hancock Pacific Expeditions in 1933, 1934, 1935, 1936, 1937, 1939, and 

 1940. All collecting was done in December, January, February, March, 

 and April. Over six hundred specimens were collected on the cruises of 

 the Velero III from the Gulf region, which represent all 3 classes of 

 sponges, 10 orders, 30 families, 56 genera, and 67 species. Twenty- six 

 new species and one new genus were found. 



The technique used in preparing the sponges is as follows: The 

 animals, on collection, were placed directly into 95 per cent alcohol. Suf- 

 ficient alcohol was added from time to time to keep the concentration 

 above 80 per cent. For making slides, a thin slice of the sponge was taken 

 perpendicularly and tangentially to the surface. This was done with a 

 razor blade, as considerable depth was needed on the slide for proper 

 identification. Sections up to .5 mm were used with good results. The bits 

 of sponge were placed directly on the slide and flooded with 95 per cent 

 alcohol, to which a small amount of basic fuchsin had been added. This 

 solution was then blotted off. Absorbent paper toweling was found to be 

 excellent for this purpose. Then the specimen was washed with absolute 

 alcohol, blotted, and cleared with a saturated solution of carbol-xylene. 

 The carbol-xylene was then removed with clear xylene and again blotted. 

 Balsam was placed on the specimen and the cover slip pressed into place. 

 A heavy balsam, warmed to the proper fluidity, was used without injury 

 to the specimen. This was an advantage because the sections were rather 

 thick and light balsam tended to run from under the cover slip. 



The system of identification used throughout this paper follows the 

 revision made by M. W. de Laubenfels (1936). The only other modern 

 system is that of Hentschel ( 1923). His classification was very incomplete 

 in the class Demospongia. He dealt with only 340 genera of the 602 

 definitely established in his time. 



