604 COLLBCnONS PROM THE WB8TEEN rNBIAN OCEAIT. 



skeleton — primary fibres vertical to surface, about a spicule's length, 

 apart, containing 3 to 5 series of spicules ; secondaries at various 

 angles to primaries, spicules 1- or 2-serial. Sarcode rich brown, 

 subtransparent. Spicules acerate, slightly curved, tapering to sharp 

 points from about 3 diameters from ends ; size '17 by "0085 millim. 

 It branches once at an angle of about 35°, its total length is 50 

 millim. (2 inches), and it has involved a mass of Polytrema, Nulli- 

 pore, &c., in its course ; the Nullipore bears the specimen which I 

 have provisionally assigned- to Ghondrilla mixta, Schulze. 



In the character of the skeleton and the size of the spicules this 

 species resembles the British species Isodictya simulans, Bowerbank, 

 and Chcdina montoffui, Johnston ; but it has not the firm texture of 

 the former, nor the tubular form of the latter, and I have not found 

 any more nearly allied species. In spite of its repent growth I have 

 assigned it to ChaUna rather than to Gladochalina, the proportions 

 of the spicules and the character of the fibre agreeing with those 

 of typical Qhalince {Ohaliriula of Schmidt), and being in my view 

 far superior as diagnostic characters to those taken only from the 

 external habit. 



Hah. Marie Louise Island, Amirante group, 16-17 fms. 



* ACERVOCHALINA, gen. n. 



See Part I., p. 398, of this Keport. 



21. Acervoclialina fisitima, var. 

 Ohalina finitima, Schmidt, Spong. Ml. Oeh. p. 33. 



As on the North- Australian margin of the Indian Ocean, so also 

 in its North-western angle this otherwise "West-Indian* species 

 seems at home. Two specimens (the one 25 millim., the other 40 

 millim. in extreme diameter) show the essential characters of the 

 species ; the vents, however, unlike those of the Australian speci- 

 mens, are placed on the margins rather than the upper surface of 

 the sponge, and the spicules are slightly thicker than in both the Aus- 

 tralian and W.-Indian forms, viz. -003 millim. as against -0018 in 

 the one and -0025 in the other. 



Hah. Seychelle Islands, 4-12 fms. 



Distribution. See Part I., p. 399, of this Report. 



RENIERIDiE. 



Besides the probably almost cosmopolitan species Tedania digi^- 

 tata, I find that several of the representatives of this generalized 

 Family type have quite a European fades, and I have identified two 

 of them (Beniera indistineta and rosea) with British species; but 

 two members of the same genus, now described for the first time, 

 possess external characters of a definiteness and singularity unusual 



* Also British, if Chalma limhata, Bowerbani, is identified with it. 



