Sollas — On Tetractinellid Sponges. 189 



rays, 0*04 mm. long ; (4) chiaster ; rays capitate, 0*008 to 0*016 mm. 

 in diameter. 



Habitat. — Kobei, Japan. 8 to 50 fms. 



Myriaster simpiicifurca, sp. n. — Sponge small ; a single oscule 

 on upper surface. Spicules — (1) acerate, 2*0 by 0-0316 mm. ; 

 (2) fork, shaft, 2*325 by 0*055 mm. ; arms, simple, 0*37 by 

 0*054 mm. ; (3) anchor, shaft, 1*86 by 0*03 mm. ; rays, 0*12 mm. 

 long; (4) chiaster, 0*012 mm. in diameter. 



Habitat.— Station 186, lat. 10° 30' S. ; long. 142° 18' E. 8 fms. 



Myriaster toxodonta, sp. n. — Sponge small ; a few small oscules. 

 Spicules— (1) acerate, 3*42 by 0*032 mm. ; (2) fork, shaft, 3*5 by 

 0*05 mm; arms, bifurcate; primary rays, 0*095 to 0*127 mm. 

 long; secondary, 0*29 to 0*32 mm. long; (3) anchor, shaft, 3*6 by 

 0*024 mm. ; rays, 0*1114 mm. long ; (4) chiaster, 0*01 to 0*016 mm. 

 in diameter. 



Habitat.— Station 203, lat. 11° 6' N. ; long. 123° 9' E. 20 fms. 



Myriaster clavosa, Ridley. 

 Habitat. — Stations 186 and 208. 



Myriaster quadrata, sp. n. — Sponge small, a single small oscule. 

 Spicules — (1) acerate, 2*56 by 0016 mm. ; (2) fork, shaft, 3*2 by 

 0*028 mm. ; arms, bifurcate; primary rays, 0*11 mm., secondary 

 rays, 0*27 mm. long; (3) anchor, shaft, 3*14 by 0*02 mm.; rays, 

 0*1 mm. long ; (4) chiaster, 0*008 mm. in diameter. 



Habitat.— Station 212, lat. 6° 54' N. ; long. 122° 18' E. 10 fms. 



Genus 2. Pilochrota, g. n. — Oscules distinct, pores in sieves 

 overlying incurrent chones ; ectosome, thick fibrous cortex ; flesh 

 spicules, chiasters ; choanosome, as in Myriaster. Distribution : 

 Australian seas, Tahiti, West Indies, S. Atlantic. 



Pilochrota haeckeli, sp. n. — Sponge sub-globular; oscule single. 

 Spicules— (1) acerate, 2*07 by 0-046 mm. ; (2) fork, shaft, 2*18 by 

 0*055 mm. ; arms, simple, 0*24 to 0*32 mm. ; (3) anchor, shaft, 

 3*03 by 0*035 mm. ; rays, 0*16 mm. long ; (4) small acerate of the 

 cloaca ; (5) chiaster, 0-016 mm. in diameter. 



Habitat. — Zamboanga. 10 fms. 



