136 NATURAL HISTORY 



311. Trichoda comosa {Trichodina, E.). The hairy 

 Trichoda. — Size, 1- 500th of an inch. 



312. Trichoda paramaecium, E. — New species; 

 1-lOOOth of an inch. 



(B.) Rotatoria. 



313. Trichoda larus {Chaetonotus larus, E.) — This ani- 

 malcule is shewn, magnified, at figure IJG. The spe- 

 cimen from which I took the sketch was 1-lOOth of an 

 inch in length. It is quick in its movements, gliding 

 through the water, and turning every instant, as if en- 

 deavouring to conceal itself. Rotatory cilia have been 

 discovered, and a simple alimentary canal, in which latter 

 respect it is allied to the Cercaria podura (182), and the 

 genus Enteroplea (Book III.) ; all of whom have a long 

 oesophagus, and are destitute of masticating organs. 

 They form the division Trachelogastrica of Dr. E. 



314. Trichoda lunaris {Rattulus lunaris, B.) — This is 

 a long cylindrical animalcule : the head convex, and taper 

 towards the posterior, which is furnished with a single 

 tail : it is capable of inflecting the body ; hence the name 

 moon-shaped. (See Book III.) 



315. Trichoda hilunis. This animalcule differs from 

 the preceding in having two setaceous tails -, it is flatter 

 also, and when bent there is a projection on the concave 

 side, forming a double lunate figure. 



316. Trichoda rattus {Monocerca rattus, E.)— This 

 animalcule, a sketch of which is given at figure 172, 



