1920.] J. Stephenson: Oligochaeta from India and E. Persia. 207 



Prostomium epilobous \ ; a faint groove delimiting the prostomium behind. 



Dorsal pores from 4/5. 



The setal rings are often closed both dorsally and ventrally ; sometimes there is 

 a small break, but it is irregular and varying in extent, — not more than 2ab or 2yz, 

 and often less. The setae are rather small, — smaller and closer set on the ventral 

 than on the dorsal surface. The following numbers were counted : — v/59, ix/63, xii/64, 

 xix/56, and in the middle of the body 56. 



The clitellum extends over segments xiii-xvi = 4 ; it is narrowed, rather lighter 

 in colour, with visible dorsal pores and intersegmental grooves. 



On segment xviii is a deep transverse crack with corrugated anterior and 

 posterior lips, situated in the middle of the length of the segment and extending 

 transversely over the middle half of the ventral surface. It is difficult to see the 

 male pores in this groove, but they appear to be near its centre, and only separated 

 by a slight median elevation in the floor of the groove. 



The female area is a median whitish circular patch anteriorly on segment xiv. 



The spermathecal apertures are two pairs, in grooves 6/7 and 7/8 ; they are 

 small, with slightly puckered lips, rather close together, about in line with seta c or 

 the space cd. 



There are no other genital marks. 



Internal Anatomy : — Septa 4/5, 5/6 and 6/7 are thin, but increase slightly in 

 thickness progressively ; 7/8 is somewhat strengthened, and 8/9 moderately so. 

 Thence to the prostatic region all are slightly, but none much, strengthened, — 10/11 is 

 perhaps least so. 



The gizzard is small and rudimentary, in segment v. The intestine begins 

 behind the prostates. 



The last heart is in segment xiii. 



The nephridia end in the same line. 



Testis sacs are present in segments x and xi. In x the sac is lobed, distinctly 

 though not deeply, and presents the appearance of a number of ovoid lobes lying 

 side by side in transverse series ; it is continuous below the oesophagus from side 

 to side, encloses both oesophagus and hearts, and appears to be divided dorsally by a 

 median septum above the alimentary canal. In xi the sac is smaller, and lies 

 posterior and ventrally to the vesiculae séminales. 



The seminal vesicles, in segments xi and xii, have a granular surface but are not 

 otherwise lobed. Each pair is fused dorsally over the alimentary canal, so as to form 

 a single sac in each segment ; that in xi overlies the testis sac deeper in the segment, 

 — it is not an extension of the testis sac (as is described for P. himalayanus by Michael- 

 sen, 3), but has an independent attachment to the posterior face of septum 10/11. 

 In an earlier stage of development, exemplified by the second of the two specimens, 

 the sac of segment x is smaller, and does not include the alimentary canal and hearts ; 

 it grows up round them, it would appear, during its formation. 



The prostates are large, occupying segments xviii and xix, and it may be part of 

 xvii also ; they are deeply cut up by the septa, and also otherwise much indented. 



