BRITISH SPONGIADjE. 115 



Habitat. — Tenby, J. S. Bowerbank; Fowey, Cornwall, 

 Mr. C. W. Peach; Jersey, Rev. A. M. Norman. 

 Examined. — In the Uving state. 



I have seen but three good specimens of this sponge ; 

 the first I dredged in about seven fathoms, in the sound 

 between Gilter Point and St. Margaret's Island, Tenby ; 

 the second I received from Mr. Peach, who obtained it at 

 Fowey. They resemble each other very closely, but in the 

 Tenby specimen the primary branches spring from a com- 

 mon base, closely adhering to a stone, while in Mr. Peach's 

 specimen they originate at a very sUght elevation above 

 the base. The subdivisions foUow each other at very short 

 distances, and the terminations are frequently trichotomous. 

 Neither of the specimens attained the height of two inches. 

 The colour, when dry, of the Powey specimen, is nearly 

 that of a dark mahogany ; that from Tenby is of a some- 

 what grayish hue ; when fresh from the sea it was of a 

 dark gray colour, with a slight tinge of green. The sur- 

 face of the sponge, in the dried state, is abundantly and 

 strongly hispid, and is so rugged and cavernous as to 

 render it very difficult to distinguish the oscula, but they 

 appear to be few in number and irregularly dispersed. 



This sponge, at first sight, in the dried condition, might 

 be readily mistaken for a stunted variety of B. ramosa, but 

 in the living state the difference in colour and general aspect 

 would readily distinguish them. The skeleton spicula of 

 the two species also closely resemble each other in size, 

 but the spinulate character of the bases of those of D. pu- 

 milus establishes the specific character with a much greater 

 degree of certainty ; a few of them are so slightly inflated 

 at the base as to appear nearly purely acuate, but by far 

 the greater number are distinctly more or less spinulate. 

 On the contrary, the skeleton spicula of D. ramosa, what- 

 ever may be its variations in size or form, very rarely pre- 

 sent any indications of inflation of the bases of those organs. 

 The tension and internal defensive spicula of the two spe- 

 cies closely resemble each other, but in the latter of the 

 two forms those of B. pumilus are much smaller than those 



