482 Records of the Indian Museum. [Vol. VIII, 



the common duct is reached at the level of the fifth pair of legs 

 and is at this point very densely nucleated (fig. D). On the down- 

 ward course of the duct the inner la3'er gradually becomes thinner, 

 the muscular coat at the same time thickening, and after looping 

 across from the right to the left-hand side of the animal between 

 the tenth and eleventh pair of legs the muscular envelope is 

 very greatly developed, and from this point onwards the duct 

 is doubtless used for expelling the spermatophores. The lumen of 

 this ductus ejaculatorius has at first the form of a four-rayed star 

 (fig. E), further down it changes and becomes slit-shaped, while 

 for some distance in front of the genital aperture its outline is 

 conspicuously lobose (fig. F). 



In the material which I have examined I have not been able 

 to find any spermatophores completely developed, but their for- 

 mation in the spermatic duct is sufficiently far advanced to enable 

 the more characteristic features to be recognized. 



In every male I have examined the mass found in the lumen 

 of the common duct is continuous, i.e. is not divided into sepa- 

 rate spermatophores. In the case of the male figured on plate 

 xxxvi the coating of the mass is very distinctly thickened at four 

 points and it is clear that three separate spermatophores are in 

 process of development. The appearance of the contents of the 

 duct is diagrammatically indicated in fig. 2 in optical section. 

 The mass is at several points attached to the wall of the duct by 

 mucus. 



The spermatophore would appear to be about 2 mm. in length 

 when fully formed Posteriorly is a large thin-walled sac in which 

 the bulk of the sperm products are situated. The contents consist 

 of spermatozoa, apparently embedded in a structureless matrix 

 together with a few large pale yellowish granules In transverse 

 sections such granules may often be observed, along with the cut 

 heads and tails of spermatozoa arranged in a haphazard fashion 

 and not radiating from a central core as in Eoperipatus (pi. xxxvi, 

 fig D). 



In the younger spermatophores the wall of the main sac is at 

 several points longitudinally pleated in a somewhat irregular man- 

 ner ^ and this is also the case with the most fu'ly developed sper- 

 matophore, which, however, possesses in addition a thin and 

 smooth horny coat (fig. H). 



At the distal end of the main sac the diameter of the sper- 

 matophore is slightly lessened and the wall thickened, the lumen 

 being in consequence considerably reduced ; further forward a 

 small expansion with a thinner wall is to be found. Beyond this 

 again the wall is very thickly chitinized and the lumen gradually 

 disappears, giving place to a Ion.'; conical cap formed entirely of 

 chitin (fig. J). At the anterior end of the .spermatophore at least 

 four coats are to be found. 



^ This appearance is not, I believe, due to shrinkaye in preservation. 



