ART. 4 SPONGES OF CALIFORNIA DE LAUBENFELS 125 



Remarks. — All or nearly all the species of Verongia are very near 

 the genotype, V. -fistularls Lamarck, 1815, and can only be separated 

 by little differences that may well be insignificant. If the accepted 

 criteria be used, however, this form approaches in size of mesh, size 

 of fiber, and size of pith only one 

 other species of this genus, that 

 described as Aplysinu p7'ocumbe7is 

 Lendenfeld (1889, p. 416), from 

 New Zealand. That is also an 

 encrusting form, but it is de- 

 scribed with black fibers, a very figure "iL—Veronma tmona de Lauben- 

 great difference. Incidentally, f'^is- x ^^ ; typical fiber cut obliquely at 



° 1 • n 1 • T 1 o"^ point to show the lamellate, pithed 



it is very briefly and inadequately structure 

 described. 



Verongia thiona is moderately common, at times at least, in the 

 intertidal areas of southern California. I know of no other local 

 form from which it may not easily be distinguished by its tendency 

 (very common in this genus) to change from yellow to very dark 

 blue or purple upon drying. 



Order DENDROCERATINA Minchin 



Family DARWINELLIDAE Merejkowsky 

 Genus APLYSILLA F. E. Schulze 



APLYSILLA GLACIALIS (Dybowski) 



Simplicella glacialis Dybowski, 1880, p. 65. 

 Aplysilla glacialis Lendenfeld, 1889, p. 706. 



Holotype. — Location unknown. 



Type locality. — Arctic (White Sea). 



Material examined. — Numerous specimens, all collected intertidal- 

 ly at Pacific Grove, Calif., in which vicinity the species is rather 

 common. It occurs on granite bowlders fairly high up in the inter- 

 tidal zone, seeming to be a very hardy sponge. 



Description (U.S.N.M. No. 21432; B.M. No. 29.8.22.23).— Shape, 

 encrusting. Size, 1 to 2 mm thick, 5 to 6 cm in diameter. Con- 

 sistency, weakly spongy. Color in life, colorless to rosy red ; in 

 alcohol, drab. Oscules, round and scattered; about 1 mm in di- 

 ameter. Pores, not evident. Surface, superficially glabrous, with 

 conules about 1 to 2 mm high and 2 to 3 mm apart. 



Ectosomal specialization, a dermis about 8/i thick, fleshy, and 

 rather slimy. Endosomal structure, a rather dense mass of flagel- 

 late chambers and other protoplasmic structures permeated by canals 

 and dendritic fibers. Histological details: The flagellate chambers 



