356 Mr. H. J, Carter on some West-Indian 



cmrulea, Carter), whose granules or cells bear the colouring- 

 matter of the sponge (PI. XII. fig. 30, ?>, c). Spicule of one 

 kind only, viz. pin-like, smooth, slightly curved ; head globular, 

 acuminated terminally, follQwed by a narrow, annular infla- 

 tion, and then a conical shaft, which, after a short distance, 

 becomes diminished gradually to a sharp point ; about 80 by 

 l-6000th inch in its greatest dimensions (fig. 30, a) ; scattered 

 plentifully and irregularly throughout the sarcodic film of 

 which the sponge is composed. Size of largest specimen seen 

 about half an inch square. 



Hob. Marine. Growing over liard objects. 



Loc. Budleigh Salterton, S. Devon. 



Ohs. This appears to be an instance of what the Germans 

 call " symbiosis." There is very little difference, except in 

 colour, between it and the foregoing species, viz. Terjnosfugax] 

 hence I have adopted De Fonbressin and Michelotti's generic 

 name for this kind of sponge. The form of the spicules ap- 

 pears to be the same, in so far as they are not fusiform, but 

 diminish gradually from the head to the point, that of the British 

 species being the largest. As regards the colouring material, 

 this is situated in free granules (? cells) in Tetyios fugax^ 

 which in T. ccendea are in short oscillatorian sheaths. Dr. de 

 Fonbressin in his *■' Review" states that, as these sponges often 

 penetrate into the cavities of marine objects {?Vioa viridis, 

 Sdt.), the genus Terjnos establishes " une veritable transition 

 aux Eponges perforantes " (p. 49) — that is, the excavating Sube- 

 rites in my group Laxa. Of the same character appear to be 

 Bha2)hidhistia sjJectahilis and Hymerhajdiia spiniglobata (An- 

 nals, 1879, vol. iii. pp. 300 and 301, pi. xxvi. figs. 13 and 

 15, &c.). 



DONATINA. 



Turning our attention to the remaining group in the family 

 Suberitida, viz. "i)o«ai5»?«," we find its subdivision already 

 foreshadowed by the number of different sponges hastily, and 

 therefore provisionally, inserted under this heading (" Notes," 

 &c., p. 198). 



Thus all the species from Suherites ap'pendiculatus to 

 Trachya 2)ernucleata, with their like, might be included under 

 a group named " Polymastina," as stated in the '■ Annals ' of 

 1876 (vol. xviii. p. 392), which group might be again sub- 

 divided into two sections, one of which presents a delicate 

 structure and is well represented by the British species in 

 Dr. Bowerbank's third volume, ex. gr. Polymastia rohusta 

 (Mon. B. S. vol. iii. pi. x. fig. 5, 1874), and the other just 

 the opposite, viz. an intensely compact and hard structure, 



