1920.] J. Stephenson: Oligochaeta from India and E. Persia. 213 



The seminal vesicles belong to segments xi and xii. Those of a segment are fused 

 together dorsally over the alimentary canal without any hint of a division ; as already 

 mentioned, the vesicle of xi extends forwards dorsally over x as well. 



The prostates are large, occupying segments xvii to xix. They are cut up by the 

 septa, and also otherwise indented into numerous lobes. The duct is irregularly twis- 

 ted, soft, moderately long, and its ectal portion is wider than its commencement. 



The female organs have the usual situation. 



The spermathecae lie in segments vii and viii ; the posterior pair are the larger. 

 The ampulla is a considerable sac, with smooth surface, not indented. The duct is 

 separated by a constriction, and is slightly swollen below the constriction ; it is very 

 stout, — one-third as thick as the ampulla, or even at its upper end quite half as thick : 

 its length is about two-thirds that of the ampulla. Its swollen upper part corresponds 

 to the diverticulum, and spermatozoa can be seen shining through in small patches, 

 but there are no definite seminal chambers (fig. 15). 



The penial setae (fig. 16) are i°o8 mm. in length, and 20 .•* in thickness. The shaft 

 is almost straight for the greater part of its length, but has a sharp curve at its proxi- 

 mal end, resembling that of a hockey stick, and is more gently curved towards the 

 tip. The point is blunt ; and the ornamentation consists of irregularly scattered 

 minute spines on the distal portion of the shaft. 



Remarks : — This species belongs to the same group as the preceding (presence of 

 testis sacs, and character of the spermathecal diverticula). It is however well differ- 

 entiated by the presence of penial setae, and the characteristic conformation of the 

 male genital field ; the specific name refers to the large wing-like papillae of this 

 region. 



Perionyx shillongensis, sp. nov. 

 Plate IX, fig. 17. 



Shillong, Assam ; 4,500-5,000 ft. 16-20-iv-1918. N. Annandale. Two specimens 



External Characters : — Length 66 mm. ; diameter 3 mm. Colour a dusky purple 

 dorsally, passing through violet to the pale unpigmented ventral surface. Segments 

 120. The animal is circular in transverse section (the species of the genus are usually 

 more or less flattened dorso-ventrally). 



Prostomium epilobous \, tongue not cut off behind. 



Dorsal pores begin from groove 3/4. 



The setal rings present a very small and rather irregular dorsal break {zz = \\yz), 

 absent altogether in the hinder part of the body; and a small ventral break {\\ah), 

 more regular than the dorsal but absent in the posterior third. The setae are rather 

 more closely set ventrally. The following numbers were counted : — v/42, ix/46, xii/49, 

 xix/48 5 and in the middle of the body 48. 



The clitellum extends over five segments, xiii to xvii ; it is very slightly swollen, 

 and there is a slight difference in tint, but this region is otherwise unaltered. 



The male field is a white, rather swollen, transversely elongated oval area on the 

 ventral surface of segment xviii, about two and a half times as broad as long, and 



