1881.] 



THE SURVEY OF H.M.S. 'ALERT. 



115 



out, however, in almost every piece examined, and aie well pre- 

 served and constant in their positions. 



Hab. Sandy Point, 7-10 fathoms (on a piece of shell). 



This specimen is finely preserved and is probably young. 



Obs. The formation of the axial network mainly by short acuate 

 spicules, and echination of the axial column by isolated long acuates 

 in addition to the diverging columns, distinguish, at any rate by 

 the perfection to which they are here carried out, this species from 

 all the species which have been assigned to either of the closely 

 allied genera Phahellia and Bictyocylitidi-us. Tlie absence of cyHn- 

 drical spicules differentiates it from P.ventilabrum and P.folmm, Sdt., 

 but can hardly be said to ally it very closely to the other two species, 

 P. robusta and P. tenax, which are similarly circumstanced ; for in 

 the one the long isolated acuates are wanting, and in the other a 

 small spined cylindrical echinates the fibres. The long acuate occurs, 

 however, in many other Axinellida. Probably Axinella cinnamomea, 

 Sdt., from the Adriatic and Algiers, is the species most closely allied 

 to ours, of known forms — though the short acuate is scarcely bent at 

 all as it is here, and it wants the very stout long and short acuates 

 which seem to connect this species with the Atlantic species A. mas- 

 tophom, where these assume such a striking size. 



Some of the chief differences between P. cinnamomea, Sdt., and 

 this Sponge may be thus stated ; — 



Axinella cinnamomea 

 Sdt. (Adriatic and < 

 Algiers). 



Acerate Sincules. 

 ^Sharply bent, tapering 

 gradually. Size '444 

 by -01267 millim. 



Phakellia cgregia (As in preceding. Size 

 (Straits of Magel-.{ -304 by -01267 mm. 

 Ian). ( 



Shorter Slender 

 Acuate. 



Very scarce ; possibly 

 not proper to sponge; 

 slightly bent. Size 

 •2837 to '3863 by 

 -01086 to -01267 

 millim. 



Very abundant; sharp- 

 ly bent. Size -2534 

 by -0095 millim. 



Stout Acuate. 

 Wanting. 



Two sizes occur. 



Order Holorrhaphidota, Carter. 



CiocALYPTA CALVA, sp. 11. (Plate X. fig. 7.) 



Massive. Surface smooth. Structure of Sponge cavernous. 

 Colour whitish. Skeleton of widely separate spiculo- fibres rising 

 from base, where they are contorted and form a layer. Fibres stout, 

 flattened, multispicular, spicules parallel in them ; at base containing 

 a margin of sarcode of one fourth of diameter of fibre, superiorly 

 becoming approximately Holorrhaphidote ; beginning to brauch and 

 anastomose about halfway between base and dermis, ending in 

 dermal membrane in tufts of shghtly diverging spicules, which 

 spread on the membrane without meeting neighbouring tufts. 

 Dermis otherwise naked, subopaque, thin, fragile. Skcleton-spi- 

 cule acuate, slightly bent, tapering from head to a sharp point, size 

 •577 by -01267 millim. No flesh-spicule. 



8* 



