158 Mr. A. Dendj on the 



styli, 0-245 by 0*0094 millim. ; tylota (with minutely spined 

 heads), 0*2 by 0'0048 millim. (thickness of shaft) ; oxeote 

 rhaphides, 0-19 by 0-0025 millim. 



The species has already been recorded from the Mediter- 

 ranean, Atlantic, Antigua, Kurrachee, Australia, Mozambi- 

 que, and the Amirante Islands ; and for further details the 

 reader is referred to Ridley's Eeport on the Zoological Col- 

 lections of H.M.S. ' Alert ' (1884), pp. 417, 607, and to 

 Ridley and Dendy's Report on the Monaxonida dredged 

 by H.M.S. ' Challenger,' p. 51. 



lotrochota haculifera, Ridley, vsit. flabellata. 



1884. lotrochota haculifera, Ridley, Zool. Coll. H.M.S. ' Alert/ Brit. 

 Mus., p. 435. 



There are in the collection two specimens which have given 

 me a great deal of trouble in determining, and which I have 

 finally decided to regard as belonging to a variety of 

 Ridley's species lotrochota haculifera^ the types of which were 

 obtained from Port Darwin, Australia. 



Each specimen forms an irregularly shaped, flattened mass, 

 and the larger of the two measures about 160 by 110 millim., 

 and has an average thickness of about 5 millim. Both speci- 

 mens are of a dark purple colour. The dermal membrane 

 has in most parts been rubbed off, but the surface appears to 

 have been smooth, although very uneven, in life. 



The megasclera are (1) fairly stout, commonly somewhat 

 curved styli, usually sharp-pointed, size about 0*176 by 0*0063 

 millim. ; (2) straight tylota, occurring chiefly in the dermal 

 membrane, as is usually the case with diactinal megasclera, 

 size about 0*22 by 0*0048 millim. The microsclera are 

 minute amphiastra (" birotulates ") about 0*0126 millim. 

 long. 



This variety differs from the types as described by Ridley 

 (1) in the flabellate instead of lobose habit, and (2) in the 

 smaller size of all the spicules. 



AxineJla Donnani^ Bowerbank, sp. (PI. XI. fig. 1.) 



1873. Isoclictya Donnani^ Bowerbank, Proc. Zool. Soc. 1873, p. 28, 

 pi. vi. figs. 2-6. 



This remarkable and well-characterized species was origi- 

 nally described and figured by Dr. Bowerbank fourteen years 

 ago from a single dry specimen, and has not since been heard 

 of. The type specimen was obtained from the Pearl-banks, 

 Ceylon, by Mr. Holdsworth, who remarks : " The dark, 

 thick, cup-shaped sponge with undulated margin is not un- 



