NO. 2263. JSfEW AFRICAN EARTHWORMS— SMITH AND GREEN. 147 



External characters. — There is nothing to indicate that the worm 

 is not complete and that the length, 5.2 cm. and the number of 

 somites, 137, are not normal for the species. The maximum diame- 

 ter, 0.4 cm., is reached in somites 8-14; while anterior to 8 the diame- 

 ter decreases quite uniformly to the first somite, where it is about 

 0.15 cm.; posterior to 14, the decrease is very gradual to 0.35 cm. 

 near the posterior end; the trunk being nearly cylindrical through- 

 out. The prostomium is scarcely recognizable and presumably is 

 prolobic. The somites posterior to 15 are each of about one-half the 

 length of the more anterior ones, which are nearly uniform, except 

 that 1-3 are slightly shorter and 15 is about two-thirds as long as 14. 

 Intersegmental grooves are distinct and jiosterior to 16 each somite 

 has a median ridge on which the setae are borne and which is bounded 

 anteriorly by a distinct annular _ ^^r^, 



groove just in front of the setae. 

 The anterior somites are without , 



such annular grooves. _}^ ^ 



The clitellum is most obvious on 

 11-14, where the intersegmental 

 grooves are less distinct, but also 

 includes 15 and IG, which have a 

 similar glandular, thickened hy- 

 podermis, but are more sharply set 

 off by intersegmental grooves and 

 are somewhat shorter. The clitel- 

 lum is developed on the ventral as 

 well as on the dorsal surface and ^""'^- i--s™genodrilus lamuensis. seta b 



, n +1 • 1 • i-l °^ SOMITE 7. X175. C 7n, CmCULAE MUSCU- 



IS but one cell tniCk, as m other lar layer; l m, intermuscular layer; I m, 



Moniligastridae. No genital pa- longitudinal muscular layer. 



pillae are obvious, although the worm is apparently at the height of 



sexual activity. 



The setae (figs. 1 and 2) are very small, very closely paired, and no 

 sculpture nor differentiation into special forms as sexual setae has 

 been observed. Posterior to the clitellum, a«:«Z>: &c:aZ=l7: 1: 17: 

 Vf- dd is about ^^ of the circumference. These numbers are from 

 averages of several measurements. Length of setae, 0.14-0.10 mm. 



The nephridiopores are near the anterior margin of the somites, 

 and the most anterior one found is on the fourth somite. None were 

 found on 10, 11, 12, and 14. Those of 4-9, 13, and 16 are about half- 

 way from seta line cd. to the mid-dorsal line, while those of 15 and 

 17-22 are in the line cd. They are obvious only in sections, and 

 hence their position is not known posterior to 22. 



There is but one pair of spermiducal pores, and they are recogniz- 

 able only in sections. They are very close to the anterior border of 

 13 and somewhat ventrad of seta line cd. Three prostate gland pores 



