104 mr. r. B. bkduard on earthworms [June 4, 



uiid described in other species of Benhamia. The four pores of the 

 ep, rmiducal glands lie as usual upon the xviith and sixth segment-. 

 Their position corresponds to that of the ventralmost setae ; from 

 each protrudes a single penial seta, whose structure will be dealt 

 with immediately in connection with that of the male efferent 

 apparatus. A nearly circular fold of integument surrounds each 

 pore, and is continuous with a fold which demarcates a groove 

 putting the two pores of each side of the body into communication. 

 This seminal gutter has a curvature which is not usual in the 

 genus. As a rule it is absolutely straight, or, if curved, the con- 

 vcxitv of the curve is to the outside. In the present species the 

 curvature is, as may be seen in the figure, in the reverse direction, 

 the concavity of the curve being directed outwards. Between the 

 two gutters the integument is traversed by a regular series of 

 grooves which subdivide its surface as I have shown (text-fig. 12). 

 I presume that the orifices of the sperm-ducts lie in the groove on 

 each side of the body. But the groove was so deep that J was 

 unable to detect them. Moreover! am unable to assert definitely 

 whether or not the ventral pair of -eta' are present upon the xviiith 

 segment. It was thought for a time that tin: absence of these 

 setae was distinctive of the genus B nhamia {sensu tirictd) ; but, as 

 Michael-en has found that this is not always the case, the character 

 must be dropped : still it remains true that in the majority of 

 species which have been carefully examined these seta- are really 

 absent. On the clitellum generally of this worm, large though ii 

 is, the seta? are not at all conspicuous. Just behind each of the 

 anterior penial seta? and just before each of the posterior penial seta; 

 there is, to the side, an isolated and Bmallish tract of integument 

 which I regard as a genital papiUa. The two pairs of genital 

 papillae would thus appear to be situated on the border lines of 

 segments xvii./xviii. and xviii./xix. Although the appearance of 

 the integument which forms these structures does not differ 

 markedly from the appearance of the surrounding integument, vet 

 the groove which Burrounds them seems to mark them out as some- 

 thing distinct ; and they are, as 1 think, to be looked upon as 

 genital papillae, which are sometimes, though not very generally, 

 presenl in the Bpecies of this genus. I could not find either the 

 poie- of the oviduct- or those of the spermathecfs. As to the 

 latter, a dissection assured me that they are ventral in position and 

 correspond fairly closely to the position of the pores of the spermi- 

 ducal glands. 



I ni, rnal Anatomy. 



When the worm was cut open, the relative thickness of various 

 regions of the integument was found to vary considerably. 



Anteriorly to the clitellum the body-wall was much thinner than in 

 the clitellar region and behind it 1 may remark that a difference 

 of colour distinguished the two layers of the clitellar epithelium. 



Intersegmental Septa. — The considerable deficiency of septa in tin- 

 anterior region of the body may perhaps account for the thinness 



