ABRANCH1ATA. 287 



Every one knows the Common Earth-worm Lumbricus terrestris, Lin., 

 with a reddish body, that attains nearly a foot in length, and which is 

 composed of upwards of one hundred and twenty rings. Under the sixteenth 

 ring are two pores, the use of which is unknown. 



This animal traverses the soil in every direction, and swallows a quantity of 

 earth. It also eats roots, ligneous fibres, animal fragments, &c. 



NAIS, Linnceus. 



The Naides have an elongated body, the rings of which are less distinct 

 than in the Lumbrici. They inhabit holes made by them in the ooze, from 

 which one half of their body projects and is constantly in motion. Black 

 points are observed on the head of some of them, which may be taken for eyes. 

 They are small worms, whose power of reproduction is as astonishing as that 

 of the Hydrae. Several species are found in the rivers, &c. of France. 



CLIMENA, Savigny. 



The ClymencB also appear to belong to this family. Their thick body has 

 but few rings, which are mostly furnished with stout setse ; a little higher, 

 and near the back, is a bundle of finer ones. There are neither tentacula nor 

 appendages to the head. Their posterior extremity is truncated and radiated. 

 They inhabit tubes. 



FAMILY II. 



ABRANCHIATA ASETIGERA. 



THE second family consists of two great genera, both of which are aquatic. 



HIRUDO, Linnceus. 



Leeches have an oblong, sometimes depressed, transversely plicated body ; 

 the mouth is encircled by a lip, and the posterior extremity furnished with a 

 flattened disk, both of which are well adapted for adhering to bodies by a 

 sort of suction, and are the principal organs of locomotion possessed by 

 these animals ; for after extending itself, the Leech fixes its anterior extre- 

 mity and approximates the other, which in its turn adheres, to allow the 

 former to be carried forward. In several we observe on the under part of the 

 body two series of pores, the orifices of as many small internal pouches, 

 considered by some naturah'sts as organs of respiration, although they are 

 usually filled with a mucous fluid. The intestinal canal is straight, inflated 

 from space to space for two-thirds of its length, where there are two caeca. 

 The blood swallowed is preserved there, red and unchanged, for several 

 weeks. 



