dredged up from the Gulf of Manaar. 367 



preserved in spirit with the sarcode present, they would have 

 so much resembled other species of Hircinia of a like kind 

 that, after all, we should have to fall back upon the skeleton 

 for specific differences. Here, however, the clathrous charac- 

 ter and hollow condition of the mass (for its general form is 

 only represented by a comparatively thin wall of sponge) are 

 so striking, together with its great abundance and luxuriant 

 growth, if one may judge by the specimens, that it can hardly 

 fail to be recognized. 



There is a similar sponge at the Mauritius ; but although 

 it presents the same clathrous character, it is massive and 

 solid throughout, with a dark purple-red sarcode ; so there is 

 no confounding the two. But the sarcode of H. clathrata may 

 have been so coloured, or it might have had a dark dermal 

 sarcode ; for both the outer part of the Mauritius specimen and 

 H. clathrata generally are, by " washing out," of the same 

 colour. So far, then, it is desirable to see these sponges alive, 

 when, of course, the sarcode is present. Such remarks apply 

 to specimens of the Hircinida generally. My Mauritius 

 specimen came to me through Dr. Dickie in 1872, to whom 

 Col. Pike, U.S. Consul there, had sent it ; but in all proba- 

 bility the hollow species, viz. H. clathrata^ is also to be found 

 in the sea about that island. 



Ehaphidonemata. 

 Family 2. Cavochalinida. 



Group 5. TUBULODIGITATA. 

 Tuhulodigitus communis^ n. sp. 



Rhizomatous at the base, consisting of a mass of short, 

 bullate, subbranched, more or less laterally united, erect 

 digital processes, rising from an irregular spreading growth of 

 a similar kind. Stiff, resilient. Colour purple, becoming 

 light brown when washed out. Processes tubular; vents 

 single, terminal. Spicule of one form only, viz. acerate, fusi- 

 form, gradually sharp-pointed, smooth ; smaller in the axis 

 than at the circumference of the fibre. Size of specimen 

 about 9 inches in diameter each way, by 3 inches high. 



Hah. Marine. 



Loc. Gulf of Manaar. 



Ohs. In my " Notes Introductory to a Study of the Spon- 

 gida" ('Annals,' 1875, vol. xvi. p. 141) this kind of Chalina 

 has been described ; but although the character of the 

 " Family " is recorded, I had not time then to give an illus- 



