DUSEIDEIA. 183 



6. DUSEIDEIA,* Johnston. 



Character. — Sponge multiform, sessiUi imperfectly 

 cellular, composed of a gelatinous membrane or basis con- 

 taining or frosted with amorphous particles of sand. 



Proceeding on the principles adopted by Dr Fleming in 

 the division of this family, I find it necessary to form a new 

 genus with the sponges that possess the above character ; and 

 this I have named Duseideia because of its want of beauty and 

 attraction, t These sponges are evidently of a lower grade 

 in organization than the other genera. Their basis is a soft 

 gelatinous unfigured membrane becoming friable when dried, 

 and in which is imbedded or crusted a sort of gravel that seems 

 to be extraneous ; for although its particles are tolerably uniform 

 in size, and more or less perfectly cubical, yet, from their un- 

 crystalline state, their irregular aggregation, and their composi- 

 tion, which is neither siliceous nor calcareous, we conclude that 

 they are not the products of any process of secretion, or in- 



» J'v<riiJ'ii!t, — ugliness. 



■\ " riidis indigestaque moles, 



Nee quicquam nisi pondus iners ; congestaque codeni 

 None bene junctarum discoidia seinina rerum." 



Ovid. Metam. i. v. 7. 



