THE OLIGOCH^TA OF NATAL AND ZULULAND. 435 



to the calciferous glands. The intestine is pi-ovided with a 

 large typhlosole. 



Circulatory System. — The dorsal vessel is single in the 

 middle portion of the body as far as the fore-part of the 

 twelfth segment ; it is double in segments 11-9. The doubling 

 of the dorsal vessel is complete, there being no union of the 

 two vessels at the septa. Large moniliform hearts occur in 

 segments 11-9. 



Excretory System. — Excretory organs consist of small 

 meganephridia. 



Reproductive System. — Male organs: the male 

 organs of the two sides are entirely separated from each 

 other. There are two pairs of moderately large spermiducal 

 funnels in segments 10 and 11 ; those of each side are 

 enclosed in a common seminal vesicle which, ventrally to the 

 oesophagus, extends through the tenth and eleventh segments. 

 The vesicles expand laterally and are constricted by the 

 septum between the tenth and eleventh segments. The 

 basal parts of each seminal vesicle are prolonged into a very 

 small fore and a moderately small hind sperm-sac, the former 

 lying in segment 9 and the latter in segment 12. The vasa 

 deferentia are very delicate, and are separate from one 

 another at least as far as the fifteenth segment. I could not 

 trace them to the extei'nal apertures. 



SpermathecEe : there are generally four pairs which 

 project freely into the body-cavity in the form of thin-walled 

 blind sacs. In the specimen which was opened, the outer 

 spei'matheca of the left fore pair was replaced by two. 



Sexual sette : the ventral and lateral pairs of seta? of the 

 twelfth segment are each replaced by a single sexual seta. 

 These setse are about 0*68 mm. in length, and at the proximal 

 end 50 /j. in thickness. They taper towards the distal end 

 to a width of about 14 fx. They are quite straight and have 

 no external ornamentation ; but at the proximal two-thirds 

 there is a conspicuous internal structure consisting of a 

 rather rough annulation. I suppose that the ventral setse of 

 the twenty-third segment are also ti-ansformed into sexual 



