104 RHINODRTLUS TENKATEI. 



nephridia reach with the proximal extremity of their loop 

 to the middle of the dorsal surface of the intestine. Each 

 nephridium (fig. 8) has a long, tubular duct, forming a loop (a), 

 which consists of a limb that ascends and one that des- 

 cends along the wall of the intestine; the inferior portion 

 of the descending limb is widened before passing into a 

 narrower tube, which somewhat farther bends again, runs 

 back till about half its length and forms here a new loop (6). 

 The ascending limb of this loop leads into a thicker tube, 

 which forms another large loop (c) , of which the limbs are 

 spirally wound around each other. The descending limb 

 of this loop runs a short way parallel with the widened 

 portion of the duct, forms again a U-shaped bend {d) and 

 terminates in a narrow tubule , bearing at its end the 

 funnel-shaped internal opening. 



There are 3 pairs of spermathecae , opening on to the 

 exterior between the Q^^ and T^'i, the 1^^ and 8*^1, the S^^ 

 and 9^^ segment, close before the orifices of the nephridia; 

 they consist of long , flat pouches , about equally broad over 

 their whole length , only narrowing a little in the vicinity 

 of their external opening. The anterior pair of them is 

 the shortest, the posterior pair is the longest and extends 

 over five segments. Perrier could find no trace of copu- 

 latory vesicles in R. paradoxus , as I suppose , because his 

 specimens were in immature condition; in some of my spe- 

 cimens they are also absent. In the 12tli and 13*^ segment 

 lie two pairs of seminal reservoirs (testes); they consist of 

 an oblong, kidney-shaped organ, furnished at the notch 

 with a smaller lobe (fig. 6). Each pair of reservoirs is covered 

 by a common membrane , in which are also enclosed the two 

 ciliated rosettes of the sperm-ducts; the two sperm-ducts 

 of each side unite on a short distance from the reservoirs 

 in a single vas-deferens of which I was however unable 

 to detect the terminal portion. Perrier observed in R. pa- 

 radoxus only a single pair of seminal reservoirs , close 

 behind the gizzard , enclosing also the ciliated rosettes of 

 the vasa-deferentia. There is a single pair of ovaries; in 



Notes from the Leyden Museum ,5 Vol. IX. 



