180 
THE VOYAGE OF H.M.S. CHALLENGEE. 
trace of a centrum ; the two forms, though distinguishable, are so similar, that I have 
not thought it worth while to remove the sponge from the Homasterina, as it is evidently 
most closely related to Myriastra. 
Colour . — Brownish, Size, 70 mm. in height. 
Habitat. — Coast of Algiers, 
Remarks. — ^The specimen of this sponge which I have examined, I owe to the 
kindness of Professor Perrier. 
Pilochrota cingalensis, n. sp. 
Sponge ('?). 
Cortex thin, about 0’35 mm. in thickness. 
Spicules. — I. Megascleres. 1. Oxea, fusiform, frequently curved, more or less 
bluntly pointed, 1‘43 by 0'035 mm. 2. Orthotrisene, rhabdome conical, bluntly pointed 
or strongylate, 1’43 by 0'058 mm. ; cladi O’ 12 mm. in length. 3. Anatnsene, rhabdome 
cylindrical, slender, bluntly pointed or strongylate, 1‘27 by 0‘017 mm. ; cladi 0’058 
mm., chord 0'08 mm., sagitta 0'055 mm. in length. 
II. Microsclere. 4. Chiaster, actines slender, variable in number and length, 
terminally tylote, 0‘016 mm. in total diameter. 
Colour. — Light brown. 
Habitat . — Galle, Ceylon. 
Pilochrota jibrosa (0. Schmidt). 
Ancorina fibrosa, O. Schmidt, Spong. Atlant. Gebiet., p. 67, 1870. 
Sponge. — An irregular thick incrustation, with a clearly differentiated cortex. 
Spicules. — I. Megascleres. 1. Oxea, fusiform, 1’43 mm. by 0’027 mm, 2. Plagio- 
trisene. 
II. Microsclere. 3. Chiaster, centrum absent, actines slender, bacillary, tylote, 
about six to twelve in number; total diameter 0*012 mm. 
Habitat . — Florida; depth, 119 fathoms. 
Remarks. — I am indebted to Dr. Ernst Ziegler of Strasburg for the opportunity of 
examining one of Schmidt’s mounted preparations of this sponge ; like the description it 
is inadequate ; the chiasters, however, are clearly shown, and one cannot but wonder how 
Schmidt came to overlook them, they resemble those represented on our PI, XIV. 
figs. 19 and 20; the megascleres are said by Schmidt to resemble those of Ancorina 
simplicissima, 0. Schmidt. 
