SPONGITDA. 605 



in their gemis andfandly. A fifth species, assigned also to Reniera, 

 has affinities which find expression elsewhere, so far as my know- 

 ledge extends, only in Indo-Paoific waters. 



22. Reniera indistincta, var. 

 Isodictya indistincta, Bowerbank, Mon. Brit. Spang, ii. p. 290, &c. 



A specimen almost identical in form and size with that described 

 above from the Australian collections (from Torres Straits) under this 

 title: it has, however, a superficial rich umber-brpwn coloration, 

 produced by a sarcode darker than that of the same parts in the 

 Australian specimen, the external colour of which is grey. The 

 dermal skeleton-fibres are also constantly, and not merely occa- 

 sionally, biseriaUy spiculate, and the spicules measure -lO hy "008 

 miUim., instead of -IB by -0063 mUlim. The occurrence of this form 

 on the western side of the Indian Ocean, together with the dark 

 coloration (resemhling that of the British specimen), are confirmatory 

 of its identity with a British species. 



Hah. Darros Island, Amirante group, 22 fms. 



Distribution. See Part I., p. 407, of this Eeport. 



23. Beuiera rosea. 



Isodictya rosea, Bowerbank, Mon. Brit. ^ong. ii. p. 282, iii. pi. xlix. 

 figs. 12-14. 



Some small, sublobate, apparently subsessile, soft pale brown 

 specimens. Skeleton-fibre formed of uniseriaUy (rarely biseriaUy) 

 arranged spicules ; the rectangular arrangement is rather obscure. 

 Spicules curved, acerate, tapering to fine points from about 4 dia- 

 meters &om ends ; size "16 by '006 millim. Vents about 1"5 millim. 

 in diameter, placed at extremities of lobes. The agreement with 

 the British specimens is comparatively close ; the spicule in the type 

 specimen, which I have examined, is slightly shorter ; as depicted 

 by Bowerbank, the spicule is made too stout. 



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



Distribution. Tenby, Sark (Bowerbank); Kerguelen Island (Carter). 



24. Reniera camerata*. (Plate LIII. figs. H, H' ; 

 PiAiE LIV. fig. n.) 



Sponge generally subcylindrical or subcorneal, perforated above 

 , by large irregular openings ; formed of thin compact lamellae 1-2 

 millim. thick, thinning off into knife-like edges, and much folded 

 and anastomosing with each other within the sponge, so as to form 

 a labyrinthine system of passages, 3-5 millim. in diametet, chiefly 

 more or less vertical in their direction. Outer surface of sponge 

 smooth, gently undulating ; inner surface of passages very minutely 

 pitted by the openings of the excretory canals. 



Consistency of sponge-waU, in spirit, very flexible and compres- 

 * Erom camera, a chamber, in allusion to the chambered interior. 



