dredged up from the Gulf of Manaar. 47 



the same, but smaller and smooth, in an earlier stage of 

 development (fig. 9, c). No. 1 projects from a bed of no. 2. 

 Size variable ; that of the specimens about £ inch in hori- 

 zontal diameter. 



Hab. Marine. On hard objects. 



Loc. Gulf of Manaar. 



Obs. This sponge, in spiculation and arrangement of the 

 spicules, is very like Hymerhaphia vermicidata, Bk. ; indeed 

 the early form of the caterpillar-like spicule (that is, before the 

 annulations are developed) is precisely like the contort spicule 

 of H. vermiculata (tig. 9, c). 



Baculifera. 



This group was established for receiving a great number 

 of different forms of a sponge both suberitic in its consistence 

 and in the form of its spicules, but Echinonematous in their 

 arrangement, wherefore it was placed in the order Echinone- 

 mata. So far as I have had an opportunity of examining 

 these forms they have all had only one and the same form of 

 spicule, which is pin-like, with the head elongated at right 

 angles to the shaft, like that of a crutch, but so peculiar that 

 there is no mistaking it anywhere when once known. The 

 specimens which I have seen chiefly come from the south- 

 west coast of Australia ; and the first described were named 

 Caulospongia verticillaris and G. pltcata, by Mr. Saville 

 Kent (Proc. Zool. Soc. 1871), of which the former is in 

 the Liverpool Free Museum, and the latter in the British 

 Museum. I found a small fragment of this group of a light 

 brown, which is the usual colour, in two places on the 

 Melobesian nodules. 



HOLORHAPHIDOTA. 



Eenierida. 



Much information is yet needed to make the species in the 

 groups of this family clear ; for the acerate form of spicule is 

 so common among them that, unless accompanied by a flesh- 

 spicule, which is seldom the case, the descriptions only of a 

 great number of fully developed specimens can establish the 

 species. Thus in the British Museum there are two species 

 on a large, branched, stony coral from Madeira, both massive 

 and amorphous, one yellow, the other white or colourless ; 

 both belong to my group " Crassa" from the large size of 

 their spicules. The yellow one has a cylindrical spicule with 

 obtuse ends (sausage-shaped) ; the white one, a still larger 

 spicule, which is long, thick, fusiform, acerate, more like 



