366 REVISION OF THE MONAXONID SPONGES, ii., 



Tedania rubicunda. (PL xvii., fig.4; and text-fig. 11). 

 Introductory. — The type-specimen — labelled ''Pellina rubi- 

 cunda" — although somewhat at variance with the description as 

 regards spiculation, is so closely in agreement therewith, in most 

 other respects, that any doubt as to its genuineness is quite pre- 

 cluded. The spicules are not, as Lendenfeld has stated, mainly 

 tylota, but mainly styli — the former being abundant only in the 

 dermal layer; furthermore, oxea are entirely absent, the tylota 

 have conspicuously spined extremities, and the trichites are 

 minutely spinulous. Thus, the spiculation — and, I might add, the 

 general arrangement of the skeleton also — conform to those of T. 

 digitata, of which species, therefore, T. rubicunda may, for the 

 present, be considered a variety. 



Descriptioyi. — The single specimen (PI. xvii., fig. 4) is a sessile, 

 massive sponge, with a somewhat cylindriform, stoutish body, 

 about 80 mm. in diameter and 100 mm. in height ; which divides 

 above into two larger, and is provided also, towards its upper 

 aspect, with several smaller, digitiform, tapering lobes or pro- 

 cesses. There is a well-defined dermal membrane, and the surface 

 generally, except where bruised and damaged, is smootli and glab- 

 rous; the processes, however, show a few, usually quite shallow, 

 longitudinal furrows or wrinkles. According to the original 

 description, the processes are traversed by a central oscular tube, 

 and have, at their summit, a number of small oscula. The first 

 part, at least, of this statement is not strictly correct; except in 

 their lower portion, the processes are traversed by distantly 

 separated canals, and these are of small size, usually less than 1 

 mm. in diameter. These canals run longitudinally, gradually con- 

 verging as the process becomes narrower, and (perhaps not in all 

 cases) finally unite, at a variable distance from the extremity of 

 the process, to form a single fairly wide canal. This terminal canal, 

 no doubt, communicates with the exterior at the apex of the pro- 

 cess, though the manner of accomplishment of this is not apparent 

 in the present specimen ; if it is by means of oscula, as is probably 

 the case, these must be very small. The chief excurrent canals, 

 both in the processes and in the body of the sponge, are surrounded 



