a new Genus and Species of Sponges. 191 



prolongation below, whose surface, again, is characterized by 

 the presence of circular rugce of sarcode more or less reticu- 

 lated, finally opening by its contracted or narrow end into the 

 commencement of an excretory canal (PI. VII. fig. 5) ; under 

 contraction, the cup-like body is conical, puckered at the apex, 

 and vertically ribbed to the base (fig. 9 c). Vents monticular, 

 characterized by a puckered state of the dermal sarcode at their 

 openings and more or less absence of the cup-like bodies in 

 their immediate vicinity ; consisting of a prolongation of the 

 dermal sarcode, whose free margin more or less covers a sub- 

 jacent cloacal chamber, furnished with a central elevation, 

 from which radiate three or more septa, or as many as there 

 may be oscular openings into this chamber (figs. 7 & 8). 

 Parenchyma consisting of sponge-substance charged Avith the 

 curved spicule mentioned, and supported on a reticulated ske- 

 leton formed of bundles of the straight cylindrical spicules, 

 overlapping each other and bound together by non-granular 

 transparent sarcode ; superiorly attached to the dermal layer, 

 and inferiorly to the object on which the sponge grows ; per- 

 meated by small cavities and excretory canals characterized 

 by their persistent openness and by having their walls formed 

 of sarcodal rugse more or less circular, prominent, and reticu- 

 lated ; with apertures of various dimensions in the interstices, 

 for the most part continuous, at their commencement, with 

 the constricted funnel-shaped prolongations of the cup-like 

 bodies, presenting cavernous dilatations here and there in 

 their course, and finally, after uniting to form large trunks, 

 opening by the oscula into the chambers of the vents already 

 described. Spicules of two kinds, long and short ; the former 

 just three times the length of the latter. Long spicule smooth, 

 straight, slightly fusiform, almost cylindrical, abruptly termi- 

 nated, with one end a little sharper than the other ; confined 

 to the skeleton-structure of the parenchyma and the sarcodal 

 columns of the cup-like bodies. Short spicule abundant, thickly 

 spinous, slightly curved, fusiform, sharp-pointed, confined to 

 the parenchyma and dermal layer ; spines minute, erect, pyra- 

 midal. Size of specimen figured 1\ inch long by \ inch thick; 

 original mass much larger. Colour not stated. 



Hah. Eed Sea, Gulf of Suez. Sessile, spreading on rocks 

 or hard surfaces. 



Ohs. This is a very remarkable sponge, for many reasons. 

 In the first place, the cup-like bodies so much resemble those 

 of similar corals, especially when the former are rendered 

 conical and ribbed by contraction, that, in a fossilized state, 

 the cribriform disk alone could determine the point ; and to a 

 superficial observer the specimen, even when recent, might 



14* 



