I9I7-] J- Stephenson : Indian Oligochaeta. 377 



spaces. A few black spots in the bottom of the groove represent 

 the sHghtly modified penial setae ; the other setae begin some httle 

 distance outside the groove. 



The female aperture seems not to have developed. 



The spermathecal apertures are in the furrows 6/7 and 7/8 ; 

 they are small and slit-like, separated by a space equal to about 

 seven intersetal intervals, or about the same as in the case of the 

 male pores. 



Internal anatomy. — Septa 5/6 and 6/7 are thin, yj^, 8/g and 

 g/ro are slightly thickened, and the rest thin. 



There is a rudimentary gizzard in segment vi, slightly firmer 

 and paler, through the presence of muscle fibres, than the rest of 

 the oesophagus. The tube is swollen in segments xiii and xiv, and 

 on opening it longitudinal lamellae were found in this region, but 

 they were of no great height and might rather be called foldings 

 than lamellae. The intestine begins in xvii ; there is no typhlosole 

 (in the anterior part). 



The last heart is in segment xiii. 



The excretory system is meganephric ; I saw no difference 

 between the nephridia of different segments, and the ducts terminate 

 at the same level. 



Testes and funnels are free in segments x and xi. The semi- 

 nal vesicles are of moderate size, in xi and xii ; they are fused in 

 each segment dorsally over the alimentary canal ; their contour is 

 smooth, not cut up into lobes. 



The prostates, of the Phereti^na-type, are very small, and con- 

 fined to segment xviii ; the duct runs straight inwards. 



The spermathecae are two pairs, in segments vii and viii, 

 opening forwards into furrows 6/7 and y/8. They are small, with a 

 sac-like ampulla which is rather constricted at its middle, the upper 

 portion being the wider. The duct is scarcely separately dis- 

 tinguishable, and is hardly more than the narrower end of the sac ; 

 it is short and half as wide as the ampulla. There is a fairly well- 

 marked bulging on one side of the lower part of the sac in one of 

 the organs which was mounted for microscopic examination (fig. 5) ; 

 this may represent the beginning of a seminal chamber. A con- 

 nective tissue strand passes upwards from the summit of the 

 ampulla. 



The penial setae (fig. 6) are scarcely modified, and represent a 

 very early stage in their evolution (c/. P. nainiana, Michaelsen, 

 13). They have the ordinary form; in length they measure •175 

 mm., in thickness 17// ; with the high power a few fine sculpturings 

 are seen on the distal half of the shaft. 



Remarks. — Of the species of this genus which have the sper- 

 mathecal apertures in furrows 6/7 and 7/8, perhaps P. ahorensis 

 resembles the present form most closely ; but the colour, the intervals 

 between the male and spermathecal apertures respectively, the 

 position of the last heart, and the fusion of the seminal vesicles of 

 each of the two segments, seem sufficient to distinguish them. 

 Differences in the male field separate the present species from P. 



