1907.] OF AFRICAN OLIGOCH^TE WORMS. 279 



segments xi./xii. and xii./xiii. There are either three or four on 

 each side of the nerve-cord in each segment scattered between 

 the ventral region of the segment and the dorsal mid-line. 



Cojndatory glands are rather numerous in this species. There 

 are three pairs anteriorly, which lie respectively in segments x., 

 xi., and xii. Each gland is double, as is commonly the case, being- 

 composed of two sausage-shaped glands uniting to form a common 

 duct. They lie to the inside of the sperm-duct, which is almost 

 or quite in contact with them as it passes back to the external 

 pore. In addition to these three smaller pairs of glands there is 

 a single much larger pair lying two or three segments behind the 

 clitellum, and occupying a similar position in the body. Each of 

 these glands is also double ; but each tubular half is longer and 

 is coiled once upon itself. There are no conspicuous bundles of 

 genital seta? associated with any of these copulatory glands. 



The locality of the species is " Zululand." 



MlCROCH^TUS ZULUENSIS, Sp. n. 



Two fragments contained in the same tube and from the same 

 locality as the species just described clearly belong to the same 

 genus, but as plainly constitute another species of that genus 

 hithei'to undescribed. Both fragments include the entire head 

 and body for a long way behind the clitellum. I do not give 

 exact measurements ; the diameter of the anterior part of the 

 body is 12 mm. or so. The Avorms thus belong to a larger species 

 than Microchcetibs colletti. 



One of the specimens (text-fig. 86) is more fully mature than 

 the other, and there is a difierence in the number of the genital 

 papillae which is not attributable to immaturity. I am thus able 

 to give a better account of external characters. But as the worms 

 are much softened my examination of the internal anatomy has 

 led to less satisfactory results. Nevertheless, I have been able to 

 make out certain anatomical facts which are of importance in the 

 discrimination of species. 



The setfe are so minute and difficult to see upon many segments 

 that I have found it impossible to map the regions of the body 

 by their aid only. Assuming, however, that the male pores are 

 upon the border-line of segments xiv./xv., a very usual position for 

 them to occupy in this genus, and that the gizzard is in segment 

 vii., which is also the case with other species, I arrive at the 

 following determination of the position of the clitellum and of 

 other organs. 



In the fully mature individual the clitellum, recognisable on 

 the xivth segment, is completely developed on the xvth, and 

 extends to the end of the xxviiith. It is saddle-shaped, a bare 

 ventral area being left. In addition to the clitellum, segments 

 xvi.-xxii. possess on either side a longitudinal band distinct from 

 the clitellum, though of the same appearance in general, coupled 

 with slight dissimilarity in colour, which is plainly the tt(jhercula 



