12 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL.11 



Genus SIGMADOGIA de Laubenfels 



Sigmadocia edaphus de Laubenfels 



Plate 14, Figs. 27, 28 ; Plate IS, Fig. 29 



Gellius edaphus de Laubenfels, 1930, p. 28. 

 Sigmadocia edaphus de Laubenfels, 1936, p. 69. 



Diagnosis. — This is a rather massive sponge, almost stony hard, and, 

 when preserved, white in color. Oscules 1 to 2 mm in diameter are often 

 present. The surface appears to be smooth. There is a well-developed 

 dermal layer, although it is only 10 to 20 /x thick and not easily detachable. 

 Tangentially placed spicules are present in this special layer. 



The spiculation is typical of the family and genus, consisting of oxeas 

 as large as 18 by 400 /x with considerable variation down to 10 by 225 /*. 

 The microscleres are sigmas only and these average 40 ju. in length. 



Ho lo type. — U. S . N . M . 



Type locality. — Pescadero Point, California. 



Distribution. — Pescadero Point south to the Gulf of California. 



Material examined. — 

 Sta. 667-37 Carmen Island 3-12-37 120 m 



Remarks. — The oxeas in these specimens average somewhat larger 

 than the specimens from central and southern California (15 by 270 fi 

 as against 18 by 400 ;«,) ; but there is considerable variation within all 

 specimens, so that overlapping occurs at least to some extent. The micro- 

 scleres are of about the same length in specimens from all locations. 



Family Goelosphaeridae Hentschel 



Genus RHIZOCHALINA Schmidt 



Rhizochalina pacifica, new species 



Plate 15, Fig. 30 ; Plate 16, Figs. 31, 32 



Diagnosis. — The Hancock specimens of this sponge appear to be 

 oscular chimneys or lipostomous fistules torn from a basal plate or mass, 

 only fragments of which are present. 



The specimens are white, averaging about 3 cm long and from .5 cm 

 to 1 cm in diameter. The surface, which is tough and leathery, is white 

 in alcohol and pierced by abundant pores about .5 mm in diameter. There 

 are oscules at the ends of most of the chimneys. These are 2 or 3 mm in 

 diameter. The surface is slightly hispid. 



The endosome is not dense and is held together between the tough 

 ectosome and the fleshy cloacal dermis. | 



The only spicules are oxeas, which are about 30 ju, by 1,300 /x. There 

 is little size variation, although rare thinner and longer oxeas are found. 



