1908.] CAPE VERDE ISLANDS SPONGES. 767 



Sycortis quadrangidata Bowerbank (IS'orman) [2]. 



Sycandra quadrangidata Lendenfeld [17]. 



Sycon quadrangtdatuon Breitfuss [7]. 



The collection contains one small specimen of this well-known 

 species. The length of the specimen is 3*5 mm. and its width 

 1 mm. It was dredged from a depth of 10 fathoms. 



Distribution. Mediteri-anean, Stiuits of Gibraltar, coasts of Por- 

 tugal and Brittany {Schmidt [21], Haeckel [14], and Lendenfeld 

 [17]) ; Guernsey {Boioerbank [2]) ; the White Sea {Breitfuss [7]) ; 

 the Cape Yerde Islands {Crossland Collection). 



Sycon caminatum, sp. n. (Plate XL. fig. 4 & text-fig. 161.) 



Mr. Crossland collected ten specimens of this new sponge, 

 several of which are quite young individvials. The general form 

 assumed by this Sycon is shown in Plate XL. fig. 4. It grows 

 erect, either singly or in groups, and its gi-eatest diameter is about 

 one quarter its height. The largest specimen has a length (ex- 

 cluding the proboscis or peristome) of 14 mm. and its greatest 

 width is 4 mm. The terminal osculum in this specimen has a 

 diameter of TS mm. A very characteristic and well-developed 

 peristome or proboscis is present in all cases, and from this struc- 

 ture I have derived the specific name. The length of this peri- 

 stome is variable ; in one specimen it reaches as much as 4 mm., 

 the length of the body of the sponge being only 8 mm. There is 

 no true oscular crown. 



The general structure of the sponge and the character of the 

 body-wall are typical of the genus Sycon. There are radial 

 chambers stretching through the whole thickness of the body-wall, 

 crowned by tufts of oxea, and flanked by definite incurrent canals. 

 There is a well-developed gastral cortex. The body of the sponge 

 is nearly circular in transverse section. The thickness of the 

 body- wall in the middle of the sponge, and therefore the length 

 of the radial chambers, is 1 mm. The breadth of the radial 

 chambers at their distal ends is 0'16 mm., and at their proximal 

 ends O'l mm. ; they are either spherical or somewhat ellipsoid in 

 cross-section. The inter-canaLs open widely on to the exterior at 

 their distal ends, are irregularly ellipsoid or nearly circular in 

 cross-section, and have about the same diameter as the radial 

 chambers; their length is equal to the thickness of the wall, 1 mm. 

 The ai^rangement of the radial chambers, and the manner in which 

 their crowning tufts of oxea project from the surface, are so 

 regular that under an ordinary hand-lens the surface of the sponge 

 gives an appearance of almost chess-board regularity. The dis- 

 tance which divides these crowning tufts from each other is, in 

 the middle portion of the sponge, about 0-16 mm. 



Colour (in alcohol) light brown. 



The Skeleton consists of triradiates, quadrii'adiates, and oxea, 

 and may be said to consist of four divisions : (1) that of the radial 

 chambers, (2) that of the tufts of spicules at the ends of the radial 

 chambers, (3) that of the gastral cortex, and (4) that of the 

 peristome. 



Proc. Zool. Soc.~1908, Xo. XLIX. 49 



