ART. 4 SPONGES OF CALIFORNIA de LAUBENFELS 95 



spiny monaxons, usually with toxas and palmate isochelas for micro- 

 scleres ; the generic name Clathr'm has usually been employed for this 

 group. Clathrm was erected by Schmidt (1862, p. 57) , and the geno- 

 type fixed by Vosmaer (1885, p. 356) as C. coralloides Schmidt. 

 Schmidt's description says quite plainly that his sponge had only 

 smooth spicules. Topsent (1925, p. 645) described a sponge that he 

 assumed to be the coralloides of Schmidt and that had smooth mon- 

 axons, toxas, and palmate isochelas. Topsent's identification may 

 be correct, but one can not be certain; Schmidt mentions no mi- 

 croscleres in his species at all, for example. Both Schmidt's and 

 Topsent's species, however, are clearly congeneric with the group 

 usually called Ophlitaspongia, and not with that called GlatliHa. 



Shall we drop Ophlitaspongia in favor of Glathria? Both were 

 published in 1862, Clathria in the latter part of the year. Unless 

 definite evidence is forthcoming to show that OphUtaspongia was 

 published yet later, I propose to retain it. 



Microdana Bowerbank (1862, p. 1109), genotype M. astrosan- 

 guinea Bowerbank, differs from so-called Glathria only in external 

 form, being encrusting instead of with branching and anastomosing 

 projections. It will be noted, however, that juvenile specimens of 

 the so-called Glathria are often encrusting, that the encrusting form 

 is very often the result of environmental factors such as strong cur- 

 rents, and that some species well established as Miorociona, for exam- 

 ple, M. prolifera Verrill, with old age assume the clathrous shape. 

 I see no reason for maintaining separate genera for such insignificant 

 differences, and propose that the whole group be termed Microciona. 



The most distinctive items about M. microjoanna are the very large 

 size of the coring spicules and the fact that they are stylote, instead 

 of subtylostylote. 



MICROCIONA PARTHENA de Laubenfels 



Microciona parthena de Laubenfels, 1930, p. 27. 



Holotype.— U.S. ^M. No. 21383 ; B.M. No. 29.9.30.6. 



Type locality. — Point Vincente (near San Pedro), Calif., depth 

 26 meters, November 15, 1924, dredged by the University of Southern 

 California. A second specimen (U.S.N.M. No. 21397) was taken 

 the same day and at the same locality, but at 32 meters. A third 

 was dredged south of San Pedro, depth 45 meters, other data lacking. 



DescT'iption. — Shape, amorphous to encrusting. Size, up to 2 cm 

 thick, 4 cm in diameter. Consistency, mediocre. Color in life, red ; 

 in alcohol, drab. Oscules and pores, not evident. Surface, super- 

 ficially tuberculate, the tubercles hispid. 



Ectosomal specialization, vague or wanting. Endosomal struc- 

 ture, a mass of plumose ascending columns, scarcely connected with 



