GEODIA NIGRA. 249 



by 13-22 /£ at the cladome, and 21-31 [i at the thickest point near the middle; 

 clades 55-130 /i long; clade-angles 31-53°; epirhabd 30-85 /z long. Anatriaenes: 

 rhabdome 3-5.4 mm. by 18-28 /z; clades 50-110 fi long; clade-angles 38-56°. 



Oxyasters: a large and a small kind can be distinguished; the large: from 

 six to seven rays, 3 fi thick; total diameter 36-38 fi; the small: from five to 

 ten rays, 0.7-3 /i thick; total diameter 22-29 fi; in both kinds the rays are 

 spined. Large oxysphaerasters : from twelve to twenty-six conical sharp-pointed 

 rays with a few large spines on their distal part, 1-2.2 /i thick; centrum 3.5-5 fi, 

 whole aster 12-16.5 n, in diameter. Transitions between these and the other 

 aster-forms frequent. Acanthtylasters: from four to twelve cylindroconical rays, 

 0.5-1.3 /i thick, with a terniinal verticil of stout recurved knobs or spines, which 

 together form a conspicuous acanthtyle; centrum small; total diameter 11-22 /i. 

 Small strongylosphaerastei's: from fourteen to twenty-two distally spined rays, 

 0.3-0.8 n thick; centrum 1.5-3.4 /i, whole aster 4.3-6.1 jn, in diameter. Large 

 strongylosphaerasters: rare; seventeen conical, truncate rays, 5 fi thick, smooth 

 at the sides, the convex terminal face densely covered with small spines; 

 centrum 13 /£, whole aster 23 jU, in diameter; perhaps foreign. Sterrasters: 65-76 

 by 55-68 by 42-64 /«. 



Eastern Pacific. West coast of North America; 22° 52' N. "Albatross" 

 Station 2829. 



Geodia nigra Lendenfeld. 

 Descriptive catalogue sponges Australian museum, 1888, p. 33. Tierreich, 1903. 19, p. 116. 



This description is based on an examination of part of the type specimen in 

 the British Museum. 



Massive, lobose. Inspirit: dark brown or black. Surface very uneven. 

 Cortex of ij^e 2-2.5 nmi. thick, composed of a sterraster-armour excavated at 

 very frequent intervals by large cavities, extending right through it. These 

 cavities are occupied by lacunose tissue containing minute styles and subtylo- 

 styles, which perhaps belongs to another sponge, burrowing in the Geodia. 

 (Lendenfeld, 1888, cortex 480 [x thick). 



Large choanosomal amphistrongyles: attenuated towards both ends; 1.3- 

 1.9, rarely over 2 mm. by 15-30 (x (Lendenfeld, 1888, error, tylostyles). Minute 

 dermal rhabds: mostly styles, often with annular thickening near blunt end; 

 subtylostyles exceedingly abundant, perhaps foreign, rarely amphistrongyles ; 

 190-370 by 5-11 /i (Lendenfeld, 1888, 100 by 8 (error 80) fi. Plagio-proclades: 

 rhabdome rounded or blunt pointed, 1.2-1.8 mm. by 16-33 fi (Lendenfeld, 1888, 

 40 /(); clades usually unequal, one, two, or all three reduced and terminally 



