464 ANNELIDES. 



self-impregnation. According to the observations of M. Montegre, 

 the ova descend between the intestine and tjie external envelope to 

 the circumference of the rectum, where they are hatched. The 

 young ones issue, living, from the anus. M. Leon Dufour, on the 

 contrary, affirms that their ova resemble t^jose of the Leech. The 

 nervous cord is nothing more than a crowded suite of numerous, 

 little ganglia(l). 



M. Savigny subdivides them again. 



His Enterionks have four pairs of small setae, eight in all, under 

 each ring. 



Everyone knows the Co7n7non Earth-worm — Lwnbricus terres- 

 iris, L. — with a reddish body, that attains nearly a foot in length, 

 and which is composed of upwards of one hundred and twenty 

 rings. The tubercle is near the anterior third. Under the six- 

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



This animal traverses the soil in every direction, and swal- 

 lows a quantity of earth. It also eats roots, ligneous fibres, 

 animal fragments, Sec. In the month of June it rises to the 

 surface during the night, to seek for a companion in the pro- 

 cess of copulation(2). 

 His Hypog^ones have, besides, an azygous seta on the back of 

 each ring. 



The only species known is from America(3). 

 Messrs Audouin and M. Edwards also distinguish the Trophoni/e, 

 which have four bundles of short sela: on each ring, and on the an- 

 terior extremity a great number of long and brilliant setae which 

 surround the mouth(4). 



(1) Conf. Montegre, Mem. du Mus., I, p. 242, pi. xii, and Leon Dufour, Ann. 

 des Sc. Nat. V, p. 17, and XIV, p. 216, and pi. xii, B, f. 1—4- 



See also the treatise of Moi-ren, De Lumbrici Terrestria Historiu Naturali nee 

 non Anatomica, Bruss., 1829, 4to. 



(2) What is here stated is common to many species, first ascertained by M. Sa- 

 vigny. He has distinguished twenty of them. See my Analyse des Travaux de 

 I'Acad. des Sc, 1821. M. Duges distinguishes six, but does not refer them ex- 

 actly to those of M. Savigny. 



N.B. Muller and Fabricius speak of Lumbrici with two setae to each ring, of 

 which Savigniy proposes to make hisgenus Clitellxo, {Lumbriais minutus. Fab., 

 Faun., Groenl., f. 4), and of others with four and six setae; but their description.? 

 require to be confirmed and completed ere their species can be classed. 



(3) Hypogseon hirtum, Sav., Eg., Annel., p. 104. 



(4) Trophonia barbata, Aud., and Edw., Littor., de la France, Annel., pi. x, f. 

 13—15. 



