1914-] J- Stephenson : Oligochaeta from Northern India. 353 



Curiously, the clitellum began with segment xii in one of the 

 Baroda specimens. 



Copulatory areas vary considerably ; those in IS are the onl}- 

 quite constant ones, though the pair in ft are almost so. The 

 marks in to (or rather on the posterior border of segment ix, 

 abutting on furrow to) were constant in the second batch of Pusa 

 specimens, but only occasional otherwise. The areas in 11 are 

 found occasionally, in M were seen altogether three times only; 

 once there was a similar pair in fr. 



I differ a little from Michaelsen (4) in the estimation of the 

 septa in the anterior part of the bod3^ This author mentions 

 septum -7 as being thickened, and since he does not refer to anj^ 

 septum in front of this, it is to be inferred that this is the first. I 

 find two septa, both thick and muscular, in this region (i.e. in 

 front of the space in which the gizzard is lodged) ; and these 

 are apparently i and t ; so that r and ^ are both absent, not | 

 only. vSeptum ^, as I have called it, is attached distinctly in 

 front of the intersegmental furrow f, though it does not correspond 

 to furrow [;. From the eighth to the twelfth segment also the 

 internal and external segmentation do not corres; ond; septum 9 is 

 actually situated in segment x as delimited externally by the 

 furrows, if not on a level with groove ty ; septum to is in the 

 anterior part of xi; and tt is iurther back in xi or at furrow H ; 

 septum \l in this as in most species of the genus is not well 

 marked; correspondence between internal and extenal segmenta- 

 tion is however re-established with the thirteenth segment. The 

 above reters especially to the insertion of the septa into the dorsal 

 body- wall ; ventrally, septa I and t^'o are a little furtuer forward. 



There is thus a wide interval between septa § and S, equal to 

 four external segments or more, but the internal segments ix, x, 

 xi and xii (i.e. as delimited by the septa) on the contrary are 

 narrow from front to back. Septa f , t"o, i? are all thick A pair 

 of very definite longitudinal muscular bands, one on each side of 

 the alimentary canal, and nearer the ventral than the dorsal 

 surface, stretch from septum « near its insertion into the oesopha- 

 gus backwards to septum t. 



It has been mentioned that septum \l is not well marked. It 

 might indeed, as in a number of other species of the genus, be 

 called absent; it is however represented by a mass of connective 

 tissue, which binds down the heart or lateral commissural vessel 

 of segment xi to the oesophagus; this member of the series of 

 commissural vessels is in a number of species less obvious on 

 dissection than the others, since it both lies at a deeper level and 

 is covered over by the thick investment mentioned above. 



The numbering of the segments during the dissection of most 

 of the species of Eutyplioeus is, as will be seen, not without some 

 difficulty, at least until some familiarity with the genus has been 

 obtained; for in spite of external dissimilarities the main points 

 of the internal anatomy are very uniform. The confusion arising 

 from the absence of some septa and approximation of others can. 



