1914-] J- Stephentson : Littoral Oligochaeta. 257 



Chilka survey 28 Z.E.V. ^V-^; a number of specimens. 

 ,, ,, 75 Z.E.V. -V--; two specimens. 



,, ,, 82 Z.E.V. ^-V-^; three specimens. 



Length variable in the different captures, 32-65 mm. ; diame- 

 ter maximum 2-2^ mm. Colour in general light grey throughout; 

 the first batch of specimens however were olive-green, the ante- 

 clitellar region paler, and clitellum with a reddish tinge. 



Prostomium slightly epilobous. Segments 106-10S, No dor- 

 sal pores. 



The lateral setae are not paired. In front of the clitellum 

 the setal intervals may be represented by the formula ah = iaa 

 = i;bc == Ud, aa, he and cd being thus equal to each other; or cd 

 may even be slightly greater than be. Behind the clitellum the 

 relations are nh = \aa, and aa = or slightly >bc = cd. Through- 

 out the bod^^ dd = 2cd. No ornamentation can be seen on the 

 setae even under the oil-immersion lens. 



The clitellum is absent ventrally, the ventral surface in this 

 region forming a broad groove. The clitellum extends from ^xiii- 

 xvii = 4^ (once xiii-xvii = 5). 



The male apertures are situated on small papillae in 

 segment xviii in the line of setae b. At the margins of the 

 ventral surface in xviii, and extending on to the adjacent parts 

 of xvii and xix, are a pair of very prominent longitudinal ridges, 

 white and rounded. Internal to the ridge of each side is a 

 deep depression, also, like the ridge, narrow, longitudinal, and well- 

 defined, i.e. an anteroposterior groove of the same length as 

 the ridge, which latter bounds the groove on its outer side. 

 Between the grooves of the two sides the ventral surface may 

 be slightly hollowed. The situation of the male apertures is 

 on- the inner, rather more gently sloping, wall of the longitudinal 

 grooves above described. 



The female apertures appear as two white points anteriorly 

 in xiv, nearer the groove il than the line of the setae; they are 

 one on each side of the nerve cord, which can be seen shining 

 through, and internal to the line of setae a. 



The spermathecal apertures are two pairs, on small white 

 papillae, in furrows i and f in the line of setae b. In one speci- 

 men, while three of the four apertures were in the lines of b, 

 one (left anterior] was exactly in line with the setae a. 



The genital markings are variable, (i) Most constant is 

 one in M, of an oval shape with long axis transverse ; its extent 

 varies, between setae a and a, or between h and b; the form 

 it takes also varies: — {a) It ma}'- be a depression, with a well- 

 marked lip-like margin, and thus somewhat sucker-like; (b) 

 or a broad white low papilla with a flat surface ; (c) or a 

 whij:ish well-defined area, but not raised above the general 

 surface; or (d) it may be very inconspicuous, though never, 

 so far as I observed, entirelv absent. 



