Catalogue of Norh-Calcareous Sponges. 249 



This is an extremely difficult species to characterise, and may 

 perhaps be best recognised by the subreticulate character of the 

 main skeleton, and the two very different sizes of spicules of 

 which it is composed, together with the feebly developed heads 

 to the spicules, which are often simply stylote. 



P.JV. 1129 (x); ?394. 



[S//berltes parasiticus, Carter]. 



Saberites parasitica, Carter, A.M.N.H., February, 1886, p. 119. 



Our knowledge of this species is altogether too insufficient to 

 justify its maintenance, the type being merely "a thin layer of 

 small pin-like spicules about 40 by 1 -6000th inch, together with 

 others of % Halichondria panicea about twice the length, parasiti- 

 cally covering a fucus." It is very possibly merely a young form 

 of some common species. 



P.M. sp. 11 (" Suberites parasitica, C. Type;" Reg. 86-12- 

 15-110). 



Genus Polymastia, Bowerbank. 



Sponge massive, sessile, with more or less well -developed 

 mammiform processes arising from the upper surface. Without 

 marginal fringe of spicules. Spicules often collected in strands ; 

 often simply stylote. 



Polymastia ? blcolor, Carter. 



Polymastia bicolor, Carter, A.M.N.H., February, 1886, p. 119. 



Polymastia blcolor, var. glomerata, Carter, A.M.N. H., February, 

 1886, p. 119. 



This species is by no means a satisfactory one. It appears to 

 be intermediate in structure between the genera Suberites and 

 Polymastia, the well-developed mastoid processes of the latter 

 being represented by mere warts or tubercles not sharply distin- 

 guished from the body, such as one finds in some species of 

 Spirastrella. The strands of very long and stout spicules which 

 run up into the processes of a typical Polymastia are also 

 wanting, the larger spicules referred to by Mr. Carter by no 

 means coming up to the usual standard. 



R.N. 289 (18 f; "slate-brown with a yellowish-brown tinge 

 in parts"); 538 (x, 19 f . ; "gallstone-yellow"); 878 (s. 9); 1 286 

 (18 f; " dull lemon-yellow "). 



