276 Mr. H. J. Carter on two undescribed Sponges 



it could be well examined, when, from a white aspect, it as^ 

 sumed the grey colour above mentioned. In one part it had 

 spread itself over the concavity of a small oyster-shell, but 

 had in no part acted upon it after the manner of a Gllona. 



ESPEEIADJD. 



Beside Acarnus innominaius^ two Esperiadje had grown 

 together with it, as above stated, one of which is Hymenia- 

 cidon macilenta, Bk. = Carmta macilenta^ Gray (/. c. p. 537) 

 =-Desmacidon, Sdt. {J. c. p. 76), and the other apparently a 

 new species, Esperia socialis, milii. 



They all belong to the same family, and present the same 

 hexagonal or isodictyal aspect on the surface more strongly 

 than any other sponge of this section, — growing for the most 

 part, when in shallow water, with a creeping habit, insinuating 

 themselves among the roots of Laminaria digitata and the 

 like crevices in marine objects generally, but seldom spreading 

 extensively unless in sheltered positions — or growing erect and 

 branching, except in the shrubby Esperia of the deep sea. 



The spicules of the West-Indian Carmia macilenta are 

 much the same as those of the same species which grows on 

 the south coast of Devon, viz. : — (1) acuate, fusiform, with oval 

 defined head as wide as the thickest part of the shaft (PI. XVII. 

 fig. 8, a) ; (2) bihamate, large, robust, contort, elliptico-elon- 

 gate (c) ; (3) inequianchorate, large, three-fluked (a, h) ; (4) tri- 

 curvate, thin (J), — measuring respectively 22-, 6-, 3^-, and 

 2-3-1800ths of an inch long. 



Beside these, there are a number of long, delicate, thin, 

 acuate spicules, which, accompanied by small bihamates and 

 anchorates, appear to be the early, if not aborted, stages in 

 development of the larger spicules of the same kind and form 

 respectively. 



But if spicules are developed in this way, viz. from small to 

 great, how is it that the central canal in some full-sized spi- 

 cules is so large as to reduce their shafts almost to the thinness 

 of mere shells or cases ? 



The only portion of this sponge found not being larger than 

 a pin's head, there is not sufficient for a description of it ge- 

 nerally. Its colour might have been " bright scarlet," as 

 noticed by the Bev. A. M.Norman [op. Bk.), or tawny yellow ; 

 for it occurs of both colours here ; and this again presents an- 

 other question, viz. in what states are sponges when they 

 present these colours respectively, or does the scarlet colour 

 indicate a reproductive one ? 



The spicular combination of Esperia socialis, mihi, which 



