•S:A DR MURRAY ON THE DEEP AND SHALLOW-WATER MARINE FAUNA 



*Melnderma stipkata,^ Ridley and Dendy. 

 Stylocordyla ' stipitata (Carter). 



Tetractinellida : 



*Thanea^ delicata, Sollas. 



Hexactinellida ^ : 



Aulocalyx irregularis,^ Schulze. 

 *Bcdanella pipetta, Schulze. 

 *Bathydorus spinosiis, Schulze. 

 * Caidophacus Icitus,''' Schulze. 



Farrea sp. (?). 

 * Holascus Jihulatus, Schulze. 



* ,, polejcBvii, Schulze. 

 *Hyalonema conus, Schulze. 



* ,, [Styloccdyx) clavigcrum, Schulze. 

 *' Mcdacosaccus vastus, Schulze. 

 *Pleorhabdus oviformis, Schulze. 



' The genus Mdiiderma stands in mucli the same reLation to Chondrocladia as does Axoniderma to Cladorhka, having, 

 like Axoniderma, developed a special spicule for external defensive purposes. The form of the extra spicule is, however, 

 totally different in the two cases ; and in MeUiderma it appears to be confined to the stalk, while in Axoniderma it is 

 most abundant in the body of the sponge. In both these cases it is very difficult to say whether the extra spicule ought 

 to be classed amongst megasclera or microsclera ; for the sake of convenience both will here be regarded as niicrosclera, 

 though standing on quite a ditt'erent footing from other microsclera. The form of the extra microsclera in MeUiderma 

 titipitata is as yet unparalleled. From their resemljlance to spears or darts we have derived the generic name. . . . 

 Only one perfect specimen of this sponge and one damaged one are in the collection ; in both of these the stalk is 

 encrusted by a thin, yellow, velvet-like layer of the densely packed, spear-like spicules. At first we thouglit that these 

 spicules belonged to some foreign encrusting sponge, and hence no mention of them was made in our Preliminary 

 Report, but subsequent examination has convinced us that they are proper to the species ; the fact of their occurring 

 in both specimens being strong evidence in favour of this view. An interesting point about the sponge is the position 

 in which the embryos develop. In the specimen which we cut open a number of round yellow bodies were found, each 

 enclosed in a membranous capsule around which the chelate spicules were lying in very great numbers. These embryos 

 were placed in a zone of tissue occupying aljout the centre of the spherical head, and lying immediately above the 

 expanded termination of the stalk, between the bands of spiculo-fibre which radiate from it ; this being obviously the 

 position of greatest security. — (Ridley and Dendy, Zool. Chall. Exp., part 59, pp. 102, 103.) 



- The genus Stylocordyla still stands aloof from all other Suberitid;e in its remarkable spiculation, though, as regards 

 external form, the old distinction embodied in the term Stylocordyla no longer holds good, for similar stipitate forms 

 are found to occur in the genus Suherites. . . . The external form of this sponge is very variable. Schulze, as well 

 as Carter, has already noticed that the head in young forms is more or less round ; we have to notice below a variety in 

 which the head is globular even in the adult. — (Ridley and Dendy, Zool. Chall. Exp., part 59, pp. 222, 22.3.) 



^ The genus Thenea is the characteristically deep-water genus of the Tetractinellida, the shallowest water from 



which it has yet been recorded being 78 fathoms, the deepest 1913 fathoms.— (Sollas, Zool. Chall. Exp., part 63, p. 404.) 



* It is a striking fact that [among the Hexactinellida] the Asconematidre, which occur somewhat abundantly in 



the south temperate zone, and likewise in the north, are represented in the tropics only Ijy a single species. — (ScHnLZE, 



Zool. Chidl. Kxp., part 53, p. 449.) 



'' AulocalyxArregularin appears to be widely distril>uted, since it was found both in the north and south temperate 

 zones.— (Schulze, Zool. Chall. Exp., part 53, p. 450.) 



" Caidophaciia latus was found in the south temperate zone, the other species, Caidophacus elugans, far removed in 

 the northern region.— (Schulze, Zool. Chall. Exp., part 53, p. 450.) 



