HALISARCA. 193 



of the naked mollusca, but a careful inspection easily detects 

 the diflFerence. This exhibits no trace of any ovafomi bodies 

 or cellular tissue, and contains neither crystals nor spicula, but 

 is no other thing than a mass of irregular and granulous glo- 

 bules, of great minuteness, that lie imbedded in a clear jelly, 

 covered over with a moi'e consistent and colom-ed skin. Dujar- 

 din has ascertained that when broken up, the separated masses 

 shoot out from their sides delicate prolongations or filaments of 

 various lengths, and slowly change their figure, in the same 

 manner as do the detached sarcoid pieces of the fresh-water 

 sponges. — (See woodcut, No. 9, p. 61.) 



