34 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 1 1 



erect dermal ones being the same size as those of the endosome. Among 

 them is an abundance of microscleres, which abundance is very uncommon 

 in the order Hadromerina. These are quite typical of the genus Choanites, 

 being centrotylote microstrongyles. The typical size is 2 /a by 30 [x; some 

 are as small as 1 /x, by 1 8 ju, and a few as large as 3 yu, by 36 /i." (de Lauben- 

 fels 1935, p. 10.) 



Holotype. — ^American Museum of Natural History. 



Type locality. — Lower California. 



Distribution. — Lower California and Gulf of California. 



Material examined. — 

 Sta. 579-36 San Marcos Island 3-14-36 20 m 



Sta. 1048-40 Puerto Refugio 1-26-40 Shore 



Remarks. — This sponge was originally collected from the Pacific side 

 of Lower California. 



The specimens from the Gulf follow the description of the holotype 

 very closely, although the spicules of both classes tend to range rather 

 smaller than the spicules of the specimen from the west coast. 



DELAUBENFELSIA, new genus 



Diagnosis. — This genus is established for a sponge which corresponds 

 closely in general architecture with the type of the family, but which 

 possesses the unique microscleres described below. 



Type species. — Delaubenfelsia raromicrosclera. 



Remarks. — ^This genus is named in honor of the foremost living 

 authority on the Porifera, M. W. de Laubenfels. 



Delaubenfelsia raromicrosclera, new species 

 Plate 61, Fig. 122; Plate 62, Figs. 123, 124; Plate 63, Figs. 125, 126 



Diagnosis. — Specimens of this sponge are dull drab in alcohol, stiffly 

 spongy in consistency, and superficially smooth. 



Six specimens were collected, all of which may have been torn from 

 the same mass. The specimen from which the slides were made is 6 cm by 

 6 cm by 4 cm. There is a tough cortex about 1 mm thick, which is detach- 

 able only with difficulty. The pores are not visible to the naked eye but 

 oscules 2 mm or 3 mm in diameter are occasionally found. The general 

 form appears to be cakelike and probably developed from a spherical or 

 subspherical form much as does Geodia mesotriaena on the California 

 coast. 



The gross endosome is quite solid with only very fine cavities. There 

 is evidence of radial structure. 



