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



from m J description and delineation [op. et loc. cit.), while the 

 only things that are like Esperia are the skeleton-spicule in 

 both the '^Unknown Sponge^^ and E. villosa, and the rigid 

 skeleton-fibre in the latter. Under these circumstances I 

 propose to change the name of ^^Esperia villosa " to that of 

 ^'Espen'opsis villosa,^'' and for the j^resent to place it in the 

 following group, viz. Hjmedcsmina. 



But lest it should be asked, " Why add it to Plymedesmina 

 in particular?" it may be observed that the nearest known 

 structures to Esperia have been placed in the Hymedesraina. 



Thus, in one of the massive specimens of Il/jmedesmia 

 JoJmsoni, Bk,, dredged on board H.M.S. 'Porcupine' between 

 the north of Scotland and the Faroe Islands, Avhicli had grown 

 upon a little stone, and which, being subcylindrical, is an 

 inch long by half an inch in diameter, the same kind of stelli- 

 ficate lace-like dermal structure and the same kind of rigid 

 spiculo-fibrous skeleton exists as in a similarly-constituted 

 Esj^eria. Moreover, another but membraniform specimen that 

 had grown over the surface of a Stelletta which had itself 

 grown on the branch of a stony coral obtained from the sea 

 about the island of Madeira (British Museum, no. 360 and 

 361, presented by the liev. 11. F. Lowe), is so like the dermal 

 layer of Esjjen'a that at first I took it for one, until convinced 

 to the contrary by microscopical examination, when I found 

 the skeletal spicule also to be almost identical in form with 

 that of Espen'oj accompanied, too, by a large tricurvate (PI. XL 

 fig. 20, a, h) • so tliat, but for the ])resence of that extraor- 

 dinary form of flesh-spicule (fig. 20, c, d, e), to which I shall 

 allude more particularly hereafter, these specimens might be 

 taken for those of an Esperia. Hence, with the Esperian 

 structure of the fibro- skeleton of Esperia villosa, now Esperi- 

 opsisj and its Es])erian skeletal spicule, together with the 

 extraordinary sizes of its flesh-spicules respectively (extra- 

 ordinary for a naviculiform anchorate), its massive as well as 

 membranous forms are better placed with the Ilymedesmina 

 than witli the Esperina, where their anchorates, being equi- 

 ended, would at once break down the main characteristic of 

 our group. 



It might be observed, too, tliat the forms Esperioj)sis villosa 

 and Hipnedesmia Johnsoni res])ectively were brought up in 

 the dredge together, or, at all events, at the same station, viz. 

 ''51 of 1869:" for they were in the same iar that bore this 

 label. 



This Ojiportunity also might be taken of stating what is 

 known of Uymedesruia Jo//nsoni, Bk., 1864, = Desrnacidon 

 Johnsoni, Sdt., 1870, as it has not been found to have grown 



