ISOPS CONTORTA. 



221 



Choanosomal oxyasters: Rays not numerous, smooth, pointed; centrum 

 small; total diameter 24 Oxysphaerasters: numerous conical rays; centrum 

 very large; total diameter 20 /x. Steirasters: 62 /< long and broad, 52 /j. thick. 



Western Pacific. Java Sea; Caspar Strait. 



CAMINUS (). ScHM. 



Among the megascleres are regular triaenes. The tetraxon megascleres 

 are confined to the superficial part of the sponge and arranged radially. The 

 dermal microscleres are asters. The afferents are cribriporal, the efferents larger 

 oscula. 



Four species are known, one of which, C. chinensis Lindgren, occurs in the 

 Pacific Ocean. 



Caminus chinensis Lindoren. 



Zool. anz., 1897, 20, p. 485. Zool. jahib. Syst., 1S9S, 11, p. 339, plate 17, fig. IB, plate 20, figs. 2a-e, c. 

 Lendenfi ld, Tierreich, 1903, 19, p. 92. 



Spherical or ellipsoidal, erect. Brown. Cortex very hard. 



Amphistrongyles: 720 by 24 /<. Orthotriaenes: rhabdome 460-GOO by 36 /<, 

 blunt; clades 325-540 /< long; clade-angles, according to the figure 90-100°. 



Oxyasters : centrum small ; total diameter 24-32 /i. Sphaeres : 2-5 /i in diam- 

 eter. Sterrasters: 136 by 108 by 90 /«. 



Northwestern Pacific. China Sea; Strait of Formosa. 



ISOPS Hollas. 



Among the megascleres are regular triaenes. The tetraxon megascleres 

 are confined to the superficial part of the sponge and arranged radially. The 

 dermal microscleres are asters. The afferents are uniporal; the efferents uni- 

 poral. 



Of the seventeen species known four occur in the Pacific Ocean. 



Isops contorta (Bowerbank). 



SoLLAs, Rept. voy. "Challenger," 188S, 25, p. 271. Lendenfeld, Tierreich, 1903, 19, p. 97. 

 Pachynmsiinn conlorta Bowerbank, Pioc. Zool. see. London, 1873, p. 327, plate 31, figs. 7-11. 



Branching, branches anastomosing. Dry: light brown. 



Large amphioxes: 1.838 mm. by 35 /<. Small amphioxes: about 0.5 mm. 

 long. Styles: 1.3 mm. long. Triaenes: rare. 



Oxyasters: total diameter 32 /i. Small sphaerasters: rays conical; total 

 diameter 70 /<. Sterrasters flattened, ellipsoidal, 160 /< long. 



Western Pacific. Fiji Islands. 



