BRITISH SPONGIADiE. 107! 



Internal defensive spicula, entirely spined, sub-clavated 

 attenuato-acuate, very few in number. 



Colour. — Alive, scarlet ; dried, light brown. 

 Habitat. — Douglass Bay, Isle of Man ; Strangford Lough, 

 Ireland, Dr. Dickie. 



I have seen but two specimens of this species, and neither 

 of them were in a perfect state of preservation. I am in- 

 debted to Mr. Howse, of Newcastle, for my first knowledge 

 of it. He kindly sent me for examination three small 

 pieces, the largest not exceeding two inches in length. I 

 subsequently received a specimen from Dr. Dickie, un- 

 fortunately also broken into pieces; the largest fragment 

 was about two inches long, branching dichotomously, and 

 based on a valve of a small bivalve shell covering a con- 

 siderable portion of its surface, and from this spreading 

 base, four branches appear to have sprung. 



The skeleton spicula vary considerably in size, many of 

 them are very stout and long ; the fusiform character is but 

 slightly developed, and about half of them exhibit more or 

 less traces of spinulation ; the remainder are acuate, with 

 occasionally an acerate one. The external defensive spicula 

 are of the same form as those of the skeleton, but rather 

 larger in size. Their position in the sponge is very cha- 

 racteristic of the species. I could not detect the internal 

 defensive spicula in situ in either of the specimens, but 

 among those obtained from boiling in nitric acid a portion 

 of one of the fragments sent to me by Dr. Dickie, there 

 were a few entirely spined sub-clavated, attenuato-acuate 

 spicula, agreeing perfectly with each other in their cha- 

 racters, thus affording an indication of their presence in the 

 sponge, although they could not be detected in the portions 

 I examined. 



I have dedicated this species to Mr. Howse of New- 

 castle-on-Tyne, in acknowledgment of the good service he 

 has rendered to science in this and in numerous other 

 instances. 



