236 THE VOYAGE OF H.M.S. CHALLENGER. 



form presents, however, so many peculiarities that the erection of a special genus seems 

 to be justified, even apart from the different form of the body and its microscopic 

 structure. 



In a Notice of a New Vitreous Sponge — Pheronema grayi ^ — Saville Kent first 

 justified the change of the generic title Holtenia, which had been applied by Wyville 

 Thomson to his Holtenia carpenteri, into Pheronema (Leidy), on the ground of priority, 

 since a generic agreement between the two species Pheronema annae, Leidy, and Holtenia 

 carpenteri, Wyville Thomson, cannot be doubted. He now brought forward a third 

 species — Pheronema grayi — belonging to the same genus Pheronema. Of this several 

 specimens had been procured during the expedition of the " Noma " off the coast of 

 Portugal and in the neighbourhood of Setubal, from depths varpng from 400 to 600 

 fathoms. This new species was further described and figured by Kent in the Monthly 

 Microscopical Journal (1870, p. 243). Pheronema grayi is distinguished by the 

 Portuguese fisherman as " Nidos de Mer," or " the sea bird's nest," being so named chiefly 

 on account of the very broad and depressed form of the body, which is indeed very like 

 the nest of a chaffinch, and also on account of the uniform distribution of the hair-like 

 siliceous spicules over the whole surface, but especially on the inferior arched portion. 

 These spicules are not arranged in bundles, but are isolated, and project for a greater or 

 less distance, while in some specimens they are prolonged to form a very long basal tuft. 

 Saville Kent also called attention to the fact that the shaft of the amphidiscs or 

 " recurvate birotulate spicula" appeared to him to be rougher or "more profusely 

 echinate," than in the case of the similar spicules of Pheronema carpenten. " The 

 sarcode investing and constituting the sponge body was of a brilliant orange colour." 



Under the name of Holtenia pourtalesii, Oscar Schmidt described and figured in the 

 same year 1870,^ several sacciform sponges, some of which are provided mth a superior 

 oscular opening, while others are entirely closed. The form of these types, however, 

 makes it difficult to refer them to this genus, or even to Pheronema; they are rather to 

 be related, as Carter noted in 1875,' to Rossella (or Lamiginella, Schmidt). It is 

 impossible to say whether a form designated by 0. Schmidt Holtenia saecus belongs to 

 Pheronema. It is described by 0. Schmidt as "sacciform, the wide opening having 

 very thin walls and irregularly projecting spicules." In the sarcode, according to 

 Schmidt, " innumerable small hexradiate spicules occur, besides many five-rayed spicules 

 with a projecting fifth ray, while whorl-like double anchors (amphidiscs) here and there 

 occur. The sparsely distributed large hexradiate spicules and the long spicules are 

 disposed on the incomplete meshes." 



In some Notes on Anchoring Sponges,* Gray announced his inclination to unite 



^Ann. and Mag. Nat. Hist., ser. 4, vol. vi. pp. 182-186. 



- Spongien des atlantischen Gebietes. 



^ Ann. and Mag. Nat. Hist., ser. 4, vol. xv. p. 118. 



*Ann. and Marj. Nat. Hist., ser. 4, vol. vi. pp. 309-312, 18T0. 



