ABT. 4 SPONGES OF CALIFORNIA de LAUBENFELS 69 



bank, 1866, from Great Britain. M. macilenta differs in having enor- 

 mous toxas. M. aegagrojyila. differs in that its megascleres, sigmas, and 

 toxas are 15 to 50 per cent larger than in macginitiei. "Were one to 

 .synonymize those two, macginitiei would fall as a third synonym. As 

 long as the two mentioned are retained as separate species, macgini- 

 fiei should also stand. Bowerbank put macilenta in Hymeniacidon^ 

 aegagropila in Desmaeidon; and Gray, 1867, made a genus Aegagro- 

 phila for the latter. Some recent authors, especially Wilson, 1925^ 

 synonymize macilenta with aegagropila. On the other hand, Hent- 

 schel, 1913, gives data that seem to me adequate demonstration of 

 sufficient difference to warrant retaining most of the present species 



A *===-—-— — ^ 



Figure 36. — Mycale macgirUtiei de Laubenfels, X300 



of Mycale for our convenience in discussing them, if for no other 

 reason. The differences between these others and 7nacgimtiei, though 

 not great, when taken in conjunction with the geographical loca- 

 tions, make it seem advisable to retain it and them as distinct species. 



Genus PARESPERELLA Dendy 



PARESPERELLA PSILA de Laubenfels 



P(iresp( rclla psila de Laubenfels, 1930. p. 26. 



Holotype.—V.S.'NM. No. 21478; B. M. No. 29.8.22.38. 



Type locality. — Monterey Bay, Calif., trawled by Prof. T. Skogs- 

 berg, on March 30, 1929, depth 15 meters. I found one other specimen, 

 beachworn and macerated, in the wrack at Hopkins Marine Station, 

 March 20, 1929. That the species may be moderatel}' common is 

 indicated by the frequency with which one notes the distinctive 

 serrated sigmas in sjDonges having obviously foreign spicules. There 

 is this much evidence to indicate its occurrence also in southern 

 California. 



Description. — Shape, amorphous to massive. Size, 3 cm high, 

 5 cm in diameter. Consistency, between spongy and fragile. Color 

 in life and when preserved, pale drab. Oscules, not evident. Pores, 

 50^ to 200/A in diameter ; abundant. Surface, superficially smooth. 



Ectosomal specialization, a dermal membrane, about 20/x thick. 

 It is fleshy, detachable, and contains abundant tangentially placed 

 spicules of all the sorts characteristic of the species. Endosomal 

 structure, " crumb-of -bread," with very evident threadlike fibers. 



