490 Messrs. S. O. Ridley and A. Dendy on 



osculum at the summit, and a sliort stalk. In the cortex primary 

 skeleton-fibres ascend in parallel lines from the base, crossed 

 at right angles by secondary ones. Skeletou-spicules large 

 and small acuates. 



[QuasilUna hrevis (Bovverbank) . 

 Locality. Station 49, south of Nova Scotia, 85 fath.] 



Genus Glioma (Grant). 

 Sponge of boring habit. Skeleton-spicules spinulate. 



Cliona dissimilis^ n. sp. 



Incrusting and boring into a flat porous Madreporarian 

 coral. A thin cortex incrusts the entire corallum on both 

 surfaces, varied by abundant, small, round, cushion-like 

 thickenings, each of which blocks up the entrance to an ex- 

 cavated canal. On one surface these cushions are more abun- 

 dant than on the other, and present no opening to the naked 

 eye ; they are, however, perforated by minute inhalant canals. 

 On the other surface each is perforated by a small osculum. 

 Skeleton chiefly developed in the thin cortical layer, where 

 it consists of spinulate spicules usually more or less vertically 

 placed. Spicules rather slender spinulates with very well- 

 marked " enormi "-spinulate heads ; size about "32 by "0065 

 millim. 



Locality. Station 188, south of New Guinea, 28 fath. 



Family 2. Spirastrellidse. 



With special flesh-spicules, which chiefly form a dermal 

 crust. 



Genus Spirastkella (Schmidt). 



Massive, sessile, with spinulate or acuate skeleton-spicules 

 and spinispirular flesh-spicules*. 



Spirastrella massa f, n. sp. 



Massive, large. Pale yellow. Of somewhat cheese-like 

 texture, rather spongy. Dermal membrane thin. Pores very 

 abundant in some parts. Skeleton very diffuse, with no 



• For figure wWt' Carter, Ann. & Mag. Nat. Hist. ser. 5, vol. iii. pi. xxix, 

 figs. 11, 12, which represent two forms of spinispirular spicules, 



t Represented by two large squarish blocks, evidently cut from one or 

 two large specimens. 



