Catalogue of Non-Calcareous Sponges. 23 



lotrochota coccinea, Cai'ter sp. 



Halichondria birotulata. Carter, A.M.N.H., January, 1886, 

 p. 52. 



Axinella coccinea., Carter, A.M.N.H., November, 1886, p. 378. 



Erect, lamellar to digitate, or thickly lobose. Surface smooth, 

 glabrous but uneven, sometimes minutely conulose. Yents 

 rather small, scattered. Soft and spongy, resilient, rather tender. 

 Very dark purple throughout, colouring the spirit. 



Skeleton. The main skeleton is a coarse, subrectangular but 

 irregular wide-meshed network of fibres containing many spicules 

 and a great deal of spongin. The diameter of the meshes varies 

 greatly. The primary fibres are about 0*09 mm. thick, the 

 secondaries somewhat thinner, both multispicular. There is 

 usually no skeleton at all in the dermal membrane, only occasion- 

 ally a few scattered spicules. Spicules also occur scattered 

 between the fibres of the main skeleton. 



Megascleres, slender styli, straight or slightly curved, usually 

 well-pointed, measuring about 02 by 0"00-t ram. Slight varia- 

 tions in size and proportions occur, and I have also seen a few 

 rounded at both ends (strongyla). 



Microscleres. Excessively minute amphiastra (birotulates), 

 very hai-d to find, very slender and only about 0"0072 mm. long. 

 I have not been able to resolve the terminal knobs into teeth. 



Mr. Carter identified this species with Higgin's Halichondria 

 birotidata, which is also an lotrochota. It seems to me better to 

 keep them distinct, although the species of this genus are 

 extremely hard to satisfactorily distinguish, and they may all be 

 mere local varieties of Bowerbank's /. (Halichondria) purpurea. 

 As Mr. Carter has described the same species (as shown by 

 examination of bis type from the British Museum) under the 

 name Axinella coccinea, the name coccinea may be conveniently 

 retained. 



R.N. 332 (18 f; " black, with maroon purple tint in the juice "); 

 1064 (x A); 1164 (x); 1175. 



B.M. sp. 37 ("[lotrochota] [Halichondria] birotula Higgins ;" 

 Reg. 86-12-15-109); sp. 64 {''Axinella r^rr/;/m C. Type ;" Reg. 

 86-12-15-8). 



