NO. 1 DICKINSON : SPONGES OF GULF OF CALIFORNIA 17 



which was collected in deep water. The other specimen has few micro- 

 scleres. Occasional sigmas were found in one specimen, but these may not 

 be proper. 



Holotype.—U. S.N.M. 



Type locality. — Gulf of California and west coast of Central America. 



Material examined. — 

 Sta. 559-36 Isla Partida 3- 9-36 90 m 



Sta. 560-36 Isla Partida 3-9-36 140 m 



Remarks. — Wilson, 1904, described two sponges from the west coast 

 of Central America as lophon indentatus and lophon lamella. They were 

 collected by the Albatross in 1891. As there is little to distinguish between 

 the two and as both are from the same locality, /. lamella should be placed 

 in synonymy with I. indentatus. 



Other lophon sponges reported are /. chelifer Lambe, 1893, which 

 was reported from the west coast of Canada and again from southern 

 California by de Laubenfels (variety California) and a variety of /. 

 chelifer (ostiamagna) reported by Wilson, 1904, from the eastern tropical 

 Pacific. All of these, together with /. indentatus, are very close together 

 and are probably a single species. 



Genus MYXIGHELA de Laubenfels 



Myxichela microtoxa de Laubenfels 



Plate 22, Fig. 44; Plate 23, Figs. 45, 46 



Diagnosis. — This sponge is a massive form of Myxilliidae. The sur- 

 face is broken into a closely packed mass of protuberances, between which 

 openings about 800 [i in diameter are occasionally to be seen. A surface 

 membrane, if present, is not clearly defined. The color of the preserved 

 specimen is drab throughout, and the consistency rather corklike. The 

 surface is occasionally hispid to 100 [i. 



The chief megascleres are acanthostyles which are exceptionally rough. 

 They are 20 ju. by 333 p. in average size. Dermal spicules are tylotes with 

 heads microspined. The size of these spicules is most frequently 4 /* by 

 190 p.. There are no smooth styles. The microscleres are palmate chelas, 

 which are rather consistently 15 ju, long, and toxas, which have an average 

 length of 135 /i. 



Holotype. — AHF no. 8. 



Type locality. — Between Angel de la Guardia Island and Isla Par- 

 tida ; 40 m ; nullipores. 



Distribution. — Same. 



