MEGASCOLEX SIEBOLDI. 



191 



wanting on the ventral side. This accumulation of bristles 

 on the belly is associated with a strong development of the 

 layer of circular muscles, that layer having a much lar- 

 ger diameter at the ventral than at the dorsal side. 



The openings of the copulatory pouches are situated be- 

 tween the 5th and 6th , 6th and 7th segment ; there is 

 an indistinct orièce of the oviduct on the 14th segment. 

 Each copulatory pouch consists of two parts: a large, el- 

 liptical vesicle , with a moderately developed duct , and a 

 narrow , cylindrical tube , reaching nearly half the length 

 of the large vesicle. In the 10th, 11th and 12th segment 

 we find the testicular sacs ; the vas deferens of each side 

 beginns with two funnel-form mouths , the one placed in 

 the 11th, the other in the 12th segment, both inclosed 

 within the common coat of the genital organ ; at its dis- 

 tal end the vas deferens is strongly dilated and joins the 

 efferent duct of the prostatic gland, that opens on the 

 18th segment. The prostatic glands are extraordinarily 

 developed, extending over five segments (17th — 22th); 

 they are superficially divided in a great number of poly- 

 gonal lobes, resembling somewhat the lobed kidney of 

 Phoca. 



Length of the largest specimen 70 m.m. ; number of 

 segments 100. 



Hab. Sumatra (Lebong). 



Megascolex Sieholdi n. s. 



Cephalic lobe rounded behind, reaching half the buccal 

 segment. 



Orifices of the copulatory pouches between the 6th and 

 7th , 7th and 8th , 8th and 9th segment ; opening of 

 the oviduct indistinct. Niimber of setae on each seg- 

 ment 80, but the cincture without bristles. There are no 

 papillae on the ventral side. The dorsal pores are com- 

 mencing between the 12th and 13th segment. The co- 

 pulatory pouches are situated to the number of three pairs 

 in the 7th, 8th and 9th segment; each of them consists 



Notes trom the Leyden MluseiTtia, Vol. "V. 



