180 Scientific Proceedings, Royal Dublin Society. 



the longer ray is 0*197, the two shorter, 0*106 mm. long ; 



(3) trichite forks, similar to the preceding, but smaller, and of 

 hair-like fineness; shaft, 1*162 mm. long; (3) somal anchor, a 

 fusiform shaft, with a filiform end, 6*0 by -01 mm. ; arms, 0*118 

 by 0*012 mm ; (4) radical anchors similar, but with a more mas- 

 sive head, and a distal mucrone; shaft, 6*8 by 0*0276 mm. ; arms, 

 0-154 by 0-0237 mm. ; (5) arculi and sigmellse about 0-0125 to 

 0*019 mm. long. 



Habitat- -Lat. 37° 17' S. ; long. 53° 52' W. 600 fms. 



Tetitta grandis, sp. n. — Sponge large, massive, sub-cylindrical, 

 or sub-ellipsoidal, seated on a massive base of tangled anchoring 

 spicules ; oscules numerous, simple ; surface hispid ; ectosome, a 

 fibro-vesicular collenchyme. Spicules — (1) fusiform acerate, 6-07 

 by 0075 mm. ; (2) trifid fork ; shaft cylindrical ; a filiform end ; 

 8-57 by 0-016 mm., to 11-8 by 0-032 mm. ; rays, 0-15 by 0-0118 

 tnm. ; (3) trichite fork, with one ray longer than the other two ; 



(4) somal anchor, a fusiform shaft with filiform end, 12*14 by 

 0'02 mm. ; rays, 0-16 by 0*012 mm. ; spread, 0*16 mm. ; (5) radical 

 anchors, similar, but with a thicker head and shorter, stouter rays ; 

 shaft, 31*5 by 0-315 mm. ; rays, 0*1 by 0*024 mm. ; spread, 

 0*1 mm. ; (6) arculi and sigmellse, 0*0118 mm. long. In small 

 specimens the spicules are smaller; thus, in one 18 by 13 mm. in 

 diameter, the acerate is only 3-5 mm. long, in another, 32 by 

 26 mm., it is 4*65 mm. long. 



Habitat. — Kerguelen and Christmas Island. 10-150 fms. 



Tetitta pedifera, sp. n. — Sponge small, somewhat thumb-shaped ; 

 surface hispid ; oscules numerous, small ; ectosome thin, supported 

 by numerous acerates lying parallel to its surface. Spicules — 

 (1) fusiform acerate, 3*2 by 0*03 mm. ; (2) forks, a slender shaft, 

 with a filiform end ; arms of unequal length, varying from 3 to 1 in 

 number ; shaft, 2*38 by 0*012 mm. ; arms, long ray, 0*15 mm. ; 

 two short rays, 0-06 mm. long; (3) anchors; arms reduced to one, 

 so that the spicule somewhat resembles a shepherd's crook ; shaft, 

 4*46 by 0*0276 mm. ; ray. 0-13 mm. long ; spread, 0*055 mm. 



Habitat.— 'Lat 0° 48' 30" S. ; long. 126° 58' 30" E. 825 fms. 



Genus 2. Chrotella, g. n. — The ectosome is a fibro-vesicular 



