&2 THE VOYAGE OF H.M.S. CHALLENGER. 



definite layer, at a little depth beneath the surface, we arrive at the condition of 

 Cladorhiza moniliformis. 



It is, of course, by no means impossible that perfect specimens of Cladorhiza 

 moruliformis may have a branching stem with a head at the end of each branch ; this 

 remains to be seen. In spiculation it agrees very closely with other species of the genus. 



Locality. — Station 157, March 3, 1874 ; lat. 53° 55' S., long. 108° 35' E.; Southern 

 Ocean, south-west of Australia ; depth, 1950 fathoms ; bottom. Diatom ooze ; bottom 

 temperature, 32°'l. One specimen. 



Cladorhiza longijnnna, Eidley and Deudy (PL XX. fig. 2 ; PI. XXI. figs. 4, 21). 



1886. Cladorrhiza longipimia, Ridley and Dendy, Aun. and Mag. Nat. Hist., ser. 5, vol. xviii. 



p. 342. 



This sponge (PI. XX. fig. 2) has acquii-ed the " Cririorhiza " form. It is composed of 

 an almost globular body, somewhat flattened on the lower surface, and also, though 

 over a less area, on the uj)per surface. The circumference of the flattened lower surface 

 is fringed with very long, fine, supporting processes, twenty-five or thirty in number, 

 projecting outwards and downwards, while a cii'clet of very short, stiff", stumpy processes 

 crowns the summit of the head. From the centre of the lower surface depends a long, 

 rather stout, slightly tapering root or stem. Diameter of head 5 mm. Length of root 

 27 mm. Average length of supporting processes 19 mm. Colour in spirit pale 

 yellow. Dermal membrane distinct, transparent. 



Skeleton. — Arranged in the usual " Crino7^hiza" iorm.; i.e., bauds of spiculo-fibre 

 form the axes of the various processes given off" from the body ; these are composed of 

 the usual, long, fusiform, stylote spicules. 



Spicules. — (a) Megasclera ; fusiform styli, reaching over 3 mm. in length by about 

 0'05 mm. thick, and usually much blunted at the apices. Very numerous smaller styli 

 also occur scattered about in the soft parts of the sponge, both in the dermal membrane 

 and in the deeper tissues ; these spicules vary greatly in size (measuring say about 

 I'O by 0"015 mm.). Sometimes they show a tendency towards the development of heads, 

 but it is very rarely that these are developed to the extent shown in the figure (PL XXI. 

 fig. 4), which has been unfortunately chosen. They diff"er from the larger styli in being 

 much more sharply pointed, but it would probably not be difficult to pick out an 

 intermediate series both in shape and size, (b) Microsclera ; we have found only 

 anisochelse (PL XXI. fig. 21); these are of the usual Cladorhiza form, but on the 

 lower surface of the sponge attain an unusually large size. Length from 0"034 to 

 0"06 mm. (on the lower surface of the sponge). 



The species may be recognised by the shape of the body, the great length of the 

 supporting processes and the presence of a second cii'cle of short processes around the 



