402 Mr. H. J. Carter on 



Of the remaining specimens which belong to my order 

 Psammonemata and the spiculiferous Keratosa respectively it 

 might be observed imprimis that all appear from their sar- 

 codeless state to have been gathered off a beach, and 

 they consist of : — 



1. Psammonemata. 



A single specimen, which is thick, flat, and massive, com- 

 posed of stiff amber-coloured keratose fibre, presenting small 

 penicilliform sandy tufts or tags on the surface in the midst 

 of a quantity of clear reticulated lateral tissue of the same 

 kind. 



Also an insignificant specimen of Polytherces, D. et M. 

 (Rircinia transformed by Spongiophaga communis), which 

 has overgrown some mussel-shells. 



i e* 



2. Rhaphidonemata. 



One specimen of a solid, digitate, branched form of Chalina 

 like C. polychotoma, but in which the spicule, instead of being 

 acerate, fusiform, and sharp-pointed, as is usually the case, is 

 acerate, curved, cylindrical, and round at the ends, sausage- 

 like, about l-300th in. long (PI. XIV. fig. 12). 



This is of much interest, because I have lately received 

 from Mr. B. W. Priest a fragment of a similar species in 

 which the spicule is of the same form but four times larger, 

 and said to have come from the Mauritius (fig. 13), since 

 it closely approaches both in general form and in that of 

 the spicules the freshwater sponge " Uruguaya " from South 

 America, in which no statoblast has yet been found (' Annals/ 

 1881, vol. vii. p. 100, pi. vi. fig. 17), thus favouring the 

 opinion of some that such sponges at least have had a marine 

 origin. For this variety I would propose the name of Chalina 

 polychotoma, var. mauritiana. Like Uruguaya corallioides , 

 too, the Mauritius specimen presents its spicule in several 

 stages of development, but none are microspined like those 

 of that species, and it lias a minute acerate flesh-spicule. 



Four specimens of Tuba lineata, var. Jlabelliformis, D. et 

 M., vasiform, with appressed sides, wherein the spicules of 

 the fibre, which are of the usual form, viz. acerate, fusiform, 

 smooth, curved, and sharp-pointed, are scanty, while the 

 keratose element of course predominates. Hence their tough 

 consistence and brown colour. 



Two other specimens of a similar kind, but more open, in 

 which the same form of spicule predominates instead of the 



