DUSEIDEIA. 187 



the animal resides in an elongated conical tube, which is con- 

 structed in the most symmetrical and beautiful manner of gi-ains 

 of sand cemented together by a strong cartilaginous or horny 

 matter ; but in no instance that I am aware of have we found 

 the animal skeleton formed from extraneous material, as in this 

 curious and new form of sponge." 



1. L). FRAGn^is, amor pilous, " fragile, friable, coarsely 

 reticulated, the fibres rugose, as if covered icith minute sandJ" 



Plate XIII. Fig.^ ; and Plate XIV. Fig. 4. 



Spongia fragilis, Montagu in Wern. Mem. ii. 114, pi. 16, f]g. 1, 2. 

 Grai/, Brit. PI. i. 360. Flem. Br. Anim. 526. Templeton in 

 Mag. Nat. Hist. ix. 471. 



Hah. Coast of Devon, Montagu. Scarborough, 3Ir Bean. 

 Found on various marine substances dredged up in Belfast 

 Lough, Templeton. Isle of Man, E. Forbes. 



Sponge without form or beauty, sessile, massive, of a coarse 

 texture and earthy brown colour, irregularly cellular, incom- 

 pressible and inelastic, tenacious enough and gritty to the feel 

 when recent or wetted, but, when dry, friable and easily moul- 

 dering between the fingers into a coarse powder. The sponge 

 is composed of a gelatinous membrane formed into a nide cel- 

 lular mass, the divisions between the cells being crusted over 

 with arenaceous particles, which give the membrane a frosted 

 appearance when examined with a pocket-glass. There are 

 a few irregular and perhaps adventitious spicula ; and the small 

 quantity of calcareous matter which enters into the sponge is 

 certainly so. 



It is only after the animal matter has been washed from the 

 skeleton by tossing in the sea, that this sponge can be confound- 

 ed, even by a cursory observer, with Halichondria fruticosa. 



To this descrii)tion, made from dried specimens, Mr Bower- 



