404 DK MURRAY ON THE DEEP AND SHALLOW-WATER MARINE FAUNA 



MyxiUa nobilis, 1 Ridley and Dendy. 

 *PJidkettia papyracea, 3 Ridley and Dendy. 

 *$nhcrites mollis, 3 Ridley and Dendy. 



[ Tetractinellida : 



Tetitta antarctica (Carter). Taken by Ross' Antarctic Expedition in the neighbour- 

 hood of Victoria Land (lat. 74° 30' and 77° 30' S.), 206 and 300 fathoms.] 



Hexactinellida : 



*Acanthascus grossularia, Schulze. 

 *Aulascus johnstoni, Schulze. 



Aulocalyx irregularis, Schulze. 



Chonelasma lamella, Schulze. 

 sp. (?)• 



Alc von aria : 



* Acanthogorgia ramosissima, Wright and Studer. 

 * Lophogorgia lutkeni, Wright and Studer. 



Pleurocorallium secundum, Dana. 

 *Primnoides sertularoides, Wright and Studer. 



Primnoisis antarctica (Studer). 

 *Stenella spinosa, Wright and Studer. 

 Thouarella antarctica (Valenciennes). 



,, variabilis* Wright and Studer. 



,, ,, var. brevispinosa, Wright and Studer. 



1 The species which we have called MyxiUa nobilis, and its varieties, have given us a great deal of trouble in 

 determining their true relations ; they appear to be sufficiently connected inter se to warrant us in considering them 

 all as varieties of one species, and that species perhaps finds its nearest already known ally in Bowerbank's Hymeniaridon 

 {MyxiUa) paupertas [British] ; the two species seem, however, to be distinct. — (Ridley and Dendy, Zool. Chall. Exp., 

 part, 59, p. 143.) 



2 Phakellia papyracea is a very delicate species, which perhaps comes near to Bowerbank's Isodictya wfundibuli- 

 formis [British], more especially if it should ultimately prove to be cup-shaped when perfect, but it is distinguished at 

 once and absolutely from that species by the absence of the oxeote spicules, so that further comparisons are needless. 

 In the absence of the oxeote spicules, however, it agrees with von Marenzeller's Cribrochalina ambigua [from Jan 

 Mayen], but differs widely in the size of the spicules, while there do not seem to he two distinct sizes as in our sponge. 

 —(Ridley and Dendy, Zool. Chall. Exp., part 59, p. 172.) 



8 The most remarkable features of this sponge [Suberites mollis] are its great softness and looseness of texture, as 

 compared with the more typical species of Suberites, and the reduction of the " dermal crust " of spicules, which no 

 longer forms a distinct cortical layer.— (Ridley and Dendy, Zool. Chall. Exp., part 59, p. 205.) 



4 Thouarella variabilis, of which there are numerous examples, varies to an extraordinary degree in the size of the 

 calyces, the development of the spines, and the development of the colony, without it being possible thereby to sharply 

 separate the individual forms specifically. Nevertheless one can generally distinguish the following three varieties from 

 each other : a. the type (Station 145, 310 fathoms), b. var. brevisjrinosa (Station 145, 310 fathoms), c. var. gracilis (Station 

 150, 150 fathoms).— (Wright and Studer, Zool. Chall. Exp., part G4, p. 68.) 



