1920.] J. Stephenson: Oîigochaeta from India and Ê. Persia. 209 



yz. The setae are set slightly closer ventrally than dorsally. The following numbers 

 were counted : — v/50, ix/58, xii/54, xix/48, and in the middle of the body 44. 



The clitellum is narrowed, and extends over segments xiii-xvi (= 4). It is 

 lighter in colour than the neighbouring segments, and the intersegmental grooves and 

 setae are visible. 



The male field occupies the middle of segment xviii. Here are seen a pair of 

 papillae which take up the greater part of the length of the segment (fig. 10) ; they 

 are bounded both in front and behind by a common transverse or slightly crescentic 

 groove, the anterior groove being the better marked, and are separated from each 

 other by a longitudinal groove in the middle line. On their outer margins the papil- 

 lae are not delimited from the surrounding area. The male pores are near the middle 

 line, and nearer the posterior than the anterior border of the papillae. 



The female aperture is situated in a small median circular depression, close to 

 the anterior border of segment xiv. 



The spermathecal apertures are in grooves 6/7 and 7/8, very close together, near- 

 ly in line with seta b. 



Internal Anatomy : — The first few septa (4/5-6/7) are very thin ; none are missing, 

 and none are markedly thickened, though 8/9, 9/10, 12/13, and 13/14 are slightly 

 stronger than the others. 



The gizzard, in segment v, is large and barrel-shaped ; it is rather soft, but by 

 no means vestigial. The intestine begins in xviii, but is compressed between the 

 prostates in xviii and xix. 



The last heart is in segment xiii. 



The terminations of the nephridia are apparently in the same line. 



Testis sacs are present in segments x and xi ; both are continuous dorsally over 

 the oesophagus and dorsal vessel. That hi segment x is very delicate, and has some- 

 what the appearance of a seminal vesicle ; that in xi, also delicate, is covered by the 

 seminal vesicles of the segment, to which the sac is adherent, though it can be 

 separated. 



The seminal vesicles, in xi and xii, are large, and have a granular surface, but 

 are not otherwise lobed. In xi the two vesicles are adherent in the middle line, 

 though they are separable without damage ; those in xii merely touch each other. 



The prostates are large, and take up the whole of the three segments xvii-xix ; 

 they are deeply incised by the septa, and also otherwise indented. The duct is rather 

 short, soft, irregularly twisted, and thin, but somewhat dilated at its extreme ectal 

 end. 



The female organs have the usual position. 



The spermathecal ampulla is a very irregularly lobed sac (fig. 11). The duct is 

 short, — one-fourth or one-fifth the length of the ampulla, — and marked off by a con- 

 striction at its beginning. The diverticula are small swellings, three or so in number, 

 side by side on the upper half of the duct; they have a metallic appearance, due to 

 the iridescent spermatozoa shining through. 



There are no penial setae. 



