338 Mr. A. Hancock on the Excavating Powers of Sponges, 



wide, and somewhat obtusely quadrate, a little longer than wide, 

 placed end to end and united by a slender, central, cylindrical 

 stem : terminal twigs exceedingly slender, almost linear, giving 

 off lateral shoots, and irregularly bifurcating : papillse variable in 

 size, some being nearly -^^\\i of an inch in diameter, while others 

 are very much smaller, arising from the lobes without order; 

 some of the lobes having only one papilla, others three or four. 

 Spicula y Qth of an inch long, slender, generally bent in the cen- 

 tre, tapering gradually to a sharp point at one end, and at the 

 other furnished with an elliptical head defined at its junction with 

 the shaft by a dusky line. Besides these there are other spicula 

 of a different form which are equally numerous with those just 

 described, but are much smaller and very delicate, measuring 

 scarcely |^rd their length : these smaller ones are fusiform, with 

 both extremities sharply pointed, and are suddenly bent in the 

 centre. 



This beautifully branched species occurs in British specimens 

 of Pecten mawimus, but the exact locality is not known. Three 

 examples have been procured. In all the papillary punctures are 

 very variable in size, and indistinctly indicate on the surface of 

 the shell the various ramifications of the sponge ; and in all the 

 specimens the branches could be perfectly distinguished likewise 

 on the inner surface. Here the sponge had made innumerable 

 minute punctures, which the mollusk had endeavoured to close 

 up by an accumulation of calcareous matter, covering the entire 

 track of the branches with small granules. 



The walls of the excavations of this species are strongly and 

 regularly punctured. 



C. Fryeri. PI. XIV. figs. 2, 4 & 9. 



Sponge formed of lobed branches arranged in a somewhat ra- 

 diating manner, and irregularly anastomosing, with a few scat- 

 tered, spine-like processes ; the lobes about y^o^^ ^^ ^^ mch. wide, 

 considerably elongated, with the ends truncate, and united by a 

 much-constricted central stem ; terminal twigs short, almost 

 linear, bifurcating : papillse small, arranged in a single row along 

 the branches, generally two or three to each lobe. Spicula of 

 two forms : one, considerably larger than the other, generally mea- 

 suring Yx^th of an inch in length, is straight, and furnished >at 

 one end with an oval head ; from thence it tapers imperceptibly 

 to the other extremity, which is finely pointed. The other form 

 of spiculum is almost cylindrical, slightly curved, with the ends 

 brought abruptly to sharp points. 



This beautiful species is imbedded in the shell of Placuna pla- 

 centa, in the possession of J. H. Fryer, Esq. of Whitley House, 

 fcifter whom it is named, and to whose interesting and extensive 



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