Grantia. ZOOPHYTA. SPONGIAD.E. 525 



Spongia comp. Fab. Fauna Groen. 448 — S. foliacea, Mont. Wern. 



Mem. ii. 92. t. xii S. comp. Grant, New Edin. Phil. Journ. i. lCC.-ii. 



t. ii. f. 11, 12, 13-23. — On the under side of rocks near low water- 

 mark, common. 



Length seldom above an inch, white, ovate, and of uniform thickness 

 throughout. The external surface is crowded with nnmerous spicula, thick, 

 and bent at one end, tapering to the other ; the pores on the inner surface 

 are larger, and the spicula triradiated ; besides these two well-marked forms 



of spicula, there are others linear, pointed, and of unequal lengths It is 



probable that the radiated spicula of this or the following species constitute 

 the Asterias of AValker, Test. Min. t- iii. f. 90. 



113. G. botryoides. — Tubular, branched, inosculating, with 



subclavate terminal simple orifices ; spicula triradiated. 



Spongia hot. Sol. Ell. Zooph. 190. t. 58. f. 1-4 — S. complicata, Mont. 

 Wern. Mem. ii. 97- t. 9. f. 3, 4. — At the roots of fuci, about low water- 

 mark, not uncommon. 



Branches in tufts, of a white colour, round, in some places adhering ; ex- 

 ternally the triradiated spicula are numerous ; internally they are few, and 

 the pores more obvious. The late Mr Montagu, to whom 1 communicated 

 specimens of this species, having employed lenses with very weak magnify- 

 ing powers, did not detect its peculiar spicula, and was in consequence led 

 to constitute a spurious species. 



114. G. ciliata. — Tubular, slightly contracted towards the 



terminal aperture, the margin of which is ciliated. 



Spongia ciL Fab. Fauna Groen. 448. — S. cornata, Sol. Ell. Zooph. 190. 

 t. lviii. f. 89. Mont. Wern. Mem. ii. 88 — On fuci, near low water- 

 mark, not uncommon. 



About half an inch in length, and |th in thickness ; the surface is closely 

 covered with linear pointed spicula, having a terminal direction ; in the sub- 

 stance of the sponge, besides these linear, there are other triradiated spicula. 

 The internal surface is full of irregularly shaped pores. 



115. G . pulverulenta. — Ovate, thick, pulverulent, villous. 

 Spongia ananas, var. Mont. Wern. Mem. ii. 97- t. xvi. f. 3 — On coral- 

 lines, rare. 



The substance of this species is thicker than the preceding, and the linear 

 spicula on the surface are longer and more crowded; Montagu found his 

 specimens on Cellaria scruposa ; mine were obtained from Serlularia cupressina 

 Zetland. 



113. G. nivea. — Sessile, encrusting, with minute pores and 

 circular orifices ; spicula triradiate and quadriradiate. 



Spono-ia nivea, Grant, New Edin. Phil. Journ. i. 168-11. t. ii. f. 14, 15, 



16.— Under surface of sheltered rocks, Prestonpans Bay, Frith of 



Forth. 



Crust in patches, one or two inches in diameter, and about two lines in 



thickness ; the orifices are slightly elevated, thickened at the base, and very 



thin towards the margin ; spicula unequal, the side-arms of the quadriradiate 



ones usually short. 



Sponges, the situation of which in the three preceding genera is doubtful. 

 1. S. digitata.—" With very slender, dichotomous branches, digitated at 



