176 



NATURAL HISTORy 



in good health, and the hulbous oesophagus, alimentary 

 canal, &c. may be readily discerned, as also the two pair 

 of horn-like processes on the under side. In cases of 

 danger it retires within the shell, having great muscular 

 contractibility. Found in sea water. 



413. Brachionus squamula, — This creature is covered 

 by a thin, transparent, crustaceous shield, nearly circular, 

 the fore part being, however, indented, as shewn at 

 figure 270 ; it has no caudal appendage. Found among 

 lemna. Size, l-60th of an inch. 



414. Brachionus pala (^wz/rc!(;«, Bory and E.) — The 

 shell of this animalcule is of an oval figure, with four 

 long processes in front, which are not readily seen when 

 the creature thrusts out its double rotatory organs. Dr. 

 £. has recognized in it a single eye : it has no tail, and 

 the ova are attached to the body, near to the posterior 

 extremity of the shell, as shewn in figure 269, which is an 

 under view : figure 268 is a back view, with the cilia with- 

 drawn. Found among confervae. Size, l-90lhofan inch. 



415. Brachionus hipalium. The picTc-axe Animalcule 

 is shewn, magnified, at figure 271 ; it is longer than the 

 preceding, and appears to have a double series of 

 indentations. 



416. Brachionus c/ypea<M5 is shewn at figure 2*82. 

 The upper end of the shell has only one indentation. 

 Found in sea water. 



417. Brachionus lamellaris {Slephanops, E.) is 

 sketched at figure 275. The shell extends beyond the 

 body, and is indentated at its lower extremity 5 it has two 



