274 Mr. H. J. Carter on some West-Indian 



lobes. Texture firm. Colour dark purple above, becoming 

 brown and colourless below. Surface uniformly reticulated, 

 wlierein the knots of the reticulation and the intervening lines 

 of the subjacent fibro-skeletal structure are rendered more or 

 less in relief by the extent to which the dark dermal sarcode 

 subsides between them, thus presenting a polygonally-divided 

 area, in which the larger divisions are marked by the salient 

 points of tlie knots, often filamented, and a smaller structure 

 of tlie same kind, but more delicate and soft, occupies tiie 

 interstices. Vents numerous, large and small, scattered. In- 

 ternal structure uniformly cellular, formed in the w^ay stated 

 in the last species ; traversed by the branches of the excretory 

 canal-system, which ends in the vents mentioned; fibre 

 kerasine, resilient, cored to a great extent with foreign bodies 

 (sand-grains &c.). Size of specimen, which is subglobular, 

 about 8x5x4 inches. 



Hah. Marine. Growing on hard objects. 



Log. Puerto Cabello and Nassau. 



Ohs. By comparing this with the last species, we come to 

 the conclusion tliat the chief differences arise from the fibre 

 being coarser, more generally cored with foreign bodies 

 (sand-grains &c.), and the structure less compact than that 

 of Spongia officinalis^ wherein the bibulous property on this 

 account so far exceeds that of even the finest-structured 

 Hircinia that the latter is of course never used for domestic 

 purposes. It is possible that this species may be represented 

 by de F. et M. in their figure 4, pL iv., under the name of 

 ^^ Spongia lacinnlosa^'''' if the surface-fiLaments thereon deline- 

 ated are to be identified with those often observed on the 

 waterworn parts of Hircinia caracasensis. 



PoLYTiiERSES, de F. et M. 



There are several specimens of this so-called sponge, which, 

 indeed, is no sponge at all, but a Hircinia in which the sar- 

 code has been mysteriously replaced by the parasitic filament 

 for which I have proposed the name of ^'Spongiophaga com- 

 munis.''^ I say '^ mysteriously," because no one yet has been 

 able to follow the transformation or development of the para- 

 site, or determine, if indeed conjecture, what it is ; for an 

 account of which, so far as is known, together witli an illus- 

 tration, I must refer the reader to my paper on tlie Parasites 

 of the Spongida (' Annals,' 1878, vol. ii. p. 165). 



It attacks Hircinice of different degrees of fineness of struc- 

 ture in all parts of the world, and so simulates the sponge 

 itself that de F. et M. took it for one, and called it " Poiy~ 



