3.56 MR. A. DENDT OX WEST-INDIAN CHALININE SPONGES. 



by Carter. As it is a West-Indian species, and is represented in the collection, I must 

 for the sake of completeness include it in this place. 



It is described by Carter as follows : — "Cauliform, rhizomatous, procumbent, solid, 

 throwing up thumb-like hollow processes, or simply branched, with large patulous 

 vents ; processes short, erect, annularly inflated, increasing in size upwards, and some- 

 what contracted at the orifice, which is lai-ge and circular. Texture resilient. Colour 

 pale amber or deep dark amber, bordering on purple, which is probably the real 

 colour when fresh. Surface smooth, even. Composition fibrous, resilient. Spicule of 

 one form only, viz. acerate, smooth, curved, fusiform, sharp-pointed, 20 by l|-6000ths 

 inch in its greatest dimensions, small, and scanty. Size of specimen 5^ inches high by 

 1^X7 inches square. Hab. Marine. Loc. West Indies, Grenada." 



There is an authentic specimen of this sponge, from Grenada, in the British Museum, 

 and I am therefore able to add a few observations to the above description. The 

 sponge (PI. LXII. fig. 1) consists of a dozen short tubes, arising side by side from an 

 elongated, compressed basal portion and mostly fused together laterally. The average 

 diameter of the orifices of the tubes is about 12 millim , and the thickness of their 

 walls about 5 millim. 



The skeleton (PL LVIII. fig. 4) is a beautifully symmetrical, rectangularly meshed 

 reticulation of stout horny fibre, rather sparsely cored by short, hastately pointed oxea. 

 In the secondary fibres the spicules are arranged uniserially and at some distance from 

 one another ; but in the primary fibres they are polyserially arranged and form a con- 

 tinuous axial core. The diameter of the fibres is about 0"07 millim., there being little 

 difference between the primaries and secondaries in this respect. Towards the inner 

 surface of the tube-wall the network becomes irregular and very wide-meshed. 



The dermal skeleton is a polygonally meslied retictilation of stout horny fibre, cored 

 by sparse, uniserially arranged, oxeote spicules. 



The spicules are rather short, hastately pointed oxea, or tornota, measuring about 

 0-075 by 0-0042 millim. 



As regards the structure of the skeleton this species occupies an intermediate 

 position between Siphonochalina spiculosa and Siphonochalina cerafosa, from both of 

 which, however, it differs markedly in external form. 



Locality. West Indies, Grenada. (Mr. Carter also identifies ^ with this species 

 several specimens from South Australia, collected by Mr. Bracebridge Wilson ; but 

 having had the opportunity of examining these specimens, which are now in the British 

 Museum, I cannot agree as to their identity with the types of Sijihoiiochalina 

 procumbens.) 



SiPHONOCHALiNA CERATOSA, n. sp. (Plate LVIII. figs. 1,1a; Plate LXII. fig. 2.) 



Here, again, there is only a single specimen in the collection, consisting of about twenty 

 ' Ann. & Mag. Nat. Hiet. ser. 5, vol. xvi. p. 286. 



