the Oenm Xotykus {Mich.). GOl 



This matter will be considered further in rehitioii to the 

 various orfi:aMs whieh arc councctcd with the three orifices 

 just described. 



The male pore of this species is on segment 17 and also 

 in the middle line of the ventral surface. In specimen A it 

 is very small and measures about '5 mm., and is surrounded 

 by radiately arranged folds of the skin. In 1} the equiva- 

 lent aperture is much larger, and measures 2 mm. from side 

 to side. Moreover, iu this particular worm the front margin 

 of the longitudinal orifice has two cushion-like projections 

 and the [)Osterior margin one such projection. Here, again, 

 the ditt'erences in size etc. might be explained by a con- 

 traction of the body pulling in the external aperture. It 

 will be noted anyhow that the two apertures, male and 

 female, of each of the two specimens correspond in this 

 particular — i.e., both arc retracted iu the one and both 

 expanded outwards in the other specimen. 



The external characters are to my mind alone quite 

 sufficient to distinguish the present species from Notykas 

 eDiini. The larger setae and dorsal pores of the former 

 contrast with the converse state of affairs shown in A^. embd. 

 Moreover, jNIichaelscn speaks of the orifices on either side 

 of the spermathecal pore as " kleine spaltfJh-mige Ocffnung," 

 and as ''etwas nach vorn geriickt . . . schlitzformigeu Oeff- 

 nungen," which does not tally with the wide circular orifices 

 in my specimen, which lie distinctly behind the spermathecal 

 crescent-shaped opening. That they belong, liowever, to 

 the same genus is clearly shown by the peculiar penial setae 

 figured by Michaelsen, which in both my specimens have 

 the end bent at right angles and covered with low spines, pic- 

 scnting, as ^lichaelscn points out, a resemblance to a tile. 

 It hardly seems likely that precisely the same modification 

 of the penial setse would occur in two genera. The internal 

 characters, moreover, furnish further proof of the generic 

 identity of specimens ; Imt enable me to add something to 

 what is known of the genus Xotykus, and possibly present 

 further differences between the two species. 



In considering the value of these apparent differences, 

 the greater maturity of specimens A and C must be borne 

 in mind. Thus, iu these worms the interior of segment 12 

 was fdkd with masses of sperm on both sides of the intes- 

 tine, quite blocking the coclomic cavity of that segment. Of 

 these 1 found no trace in specimen B, in which, moreover, 

 the sperm-sacs of segment 12 were much less developed. 

 These features are obviously due to different maturity. 

 Furthermore^ the male terminal apparatus differed slightly 



