192 MEGASCOLEX JAPONICUS. 



of two parts : a large pear-shaped vesicle , with a short 

 duct, and a tube, somewhat louger than the vesicle and 

 plicated like in F. Houlleti Perr. Male genital or- 

 gans placed in the 11th and 12th segment; prostatic 

 glands large, divided in lobes by deep incisions. The 5th 

 and 6th septum bear groups of glandular tubes on their 

 anterior side; the 8th and 9th septum are wanting. In 

 the 26th segment the intestine is provided on each side 

 with six conical coeca, placed on a transverse series; the 

 superior is the longest, extending forwards into the 21th 

 segment and it seems to represent the single caecum of 

 other Megascolex-^^&oiQ^. 



Length 270 m.m. ; circumference of body 30 m.m.; 

 number of segments 135. 



Hab. Japan (von Siebold). 



Megascolex japonicus n. s. 



Cephalic lobe extending nearly over half the buccal seg- 

 ment, dilating at its anterior end. 



Orifices of the copulatory pouches between the 6th and 7th , 

 the 7th and 8th segment; opening of the oviduct distinct. 

 First dorsal pore between the 11th and 12th segment. 

 Instead of the two male genital pores on the 18th ring, 

 there is on each side of the ventral median line a lon- 

 gitudinal thickening of the body wall, having about the 

 form of the letter J and extending over the 18th and 

 half the 1 7th segment ; over the middle of this ridge is 

 running a groove, which consists of a long longitudinal 

 and a short transversal part. In the latter part the geni- 

 tal pore is to be found and therefore we may suppose 

 that the ridge has some function in the act of copula- 

 ting. The number of setae on each segment amounts to 

 66. The two pair of copulatory pouches are situated in 

 the 7th and 8th segment; each pouch consists of two parts , 

 a large conical vesicle somewhat flattened at its posterior 

 part, thus resembling a racket, and a very slender tube, 



Notes from the Lieyden ]Vliiseum, Vol. "V, 



