SPONGES — WHITELEGGB. 509 



the surface exhibits numerous verruciform processes ; the latter 

 are from 2 to 3 mm. apart and from 0-5 to 1 mm. in height ; on 

 the marginal areas of the branches they are a little more promi- 

 nent. Texture rather brittle, harsh to the touch, and slightly 

 • compressible; colour yellowish-grey. 



Skeleton composed of a few very stout, axial, primary fibres, 

 from 5 to 0'8 mm, in diameter. The secondaries are given off 

 at pretty regular intervals ; they are about 0'25 mm. in diameter 

 at their origin, but as they approach the surface in graceful 

 curves they rapidly diminish in diameter and finally terminate 

 in tufts of radiating spicules, of about twelve or more. The 

 fibres consist of a large amount of dark yellow spongin ; they 

 frequently anastomose, and although the plumose ramification is 

 well marked at the sui-face, the central regions present a more 

 or less reticulate appearance. 



Megascleres : — (1) Slightly curved styli, gradually tapering to 

 acute points ; size 0-2 to 0-25 by 0-01 to 0-015 mm. (2) Curved, 

 blunt-ended styli and strongyli, the latter rather abundant ; 

 size 0'25 to 3 by 0-015 to 002 mm. (3) Oxea bent in the 

 middle ; very scarce and may not belong to the sponge. 



In my preliminary examination of this species it was noted as 

 a commensal with a gorgonoid. In the final examination I failed 

 to find the latter to fix it definitely. Still the specimen con- 

 tains abundant spicules in the verrucae, and when boiled out in 

 caustic soda they were to be seen in great numbers. The spicules 

 remind one of irregular bundles of Nostoc, being arranged in 

 bead-like lines, and in many cases they are dumbbell-shaped, but 

 perfectly smooth. Spicules of gorgonoid : — size 0-015 b}'' 0-004 

 mm. 



AXINELLA ARBORESCEN'S, Ridle^j and Dendy. 



Axinella arborescens, Ridley and Dendy, Chall. Rep., ZooL, xx., 

 1887, p. 1, 178, pi. XXXV., fig. 4-4a. 



Stations 34, 44, 53. 



Three examples of this species are in the collection ; they 

 agree in every character with the description in the "Challenger" 

 Report. 



AXINELLA FRONDULA, s^j. nov. 



(Plate xlvi., fig. 32.) 



Station 50. 



Sponge consisting of a thin frondose lamina, 75 mm. high, 50 

 mm. in width, and from 1 to 2 mm. in thickness. There is a 

 distinct flattened peduncle which gives rise to four well marked 

 lobes ; these are more or less dilated apically and either rounded 

 or truncated. 



