the Genus Notvktis {Mich.). 603 



])ciiial srtic dcscrilird above, also tend to prove generic 

 identity, though dill'ering in detail (particularly the sper- 

 niathecal sac). Tliere is in the present species clearly but 

 one pair of sperm-duct funnels, wliich lie in segment 11, and 

 one pair of sjx'rm-sacs, which are in the following segment. 



Spennathecal Sac. — The general characters of this sac 

 agree with those described by Michaelsen for Nufykus emini ; 

 but there are certain details which require emphasis. I l)ave 

 studied these in all three si)ecimens : in two by dissection 

 from above — by cutting througli the body-wall along the 

 dorsal median line ; in the third ((') by dividing the head- 

 end of the body longitudinally and examining the sac in a 

 lateral view. The latter allowed of a complete lateral 

 extcrn;il view, as the whole of the spermathecal sac was left 

 in the right half of the body after the bisection. 



In B, the immature example, the sac is divisible into 

 three regions : in the middle of a muscular region i)resenting 

 quite the appearance of a gizzard, which narrowed abruptly 

 posteriorly to form a narrovier tubular soft-walled sac ending 

 behind in a slightly dilated extremity; anteriorly the mus- 

 cular sac became a soft region rather flattened dorso- 

 ventrally, which bent down at right angles to open on to 

 the exterior by the narrow crescent-shaped external orifice, 

 already described. When cut across, the gizzard-shaped 

 median region was seen to be very thick-walled, and its 

 muscular fibres gave to it a nacreous glitter common to such 

 structuics. 



Firmly attached to the terminal region of the spermathecal 

 sac and one on each side lay two muscular bodies, spherical 

 to rather more oval in form, which have muscular walls. 

 These aie clearly the " Nebentaschcn " of Dr. Michaelsen's 

 descriptions. I did not detect in this specimen the delicate 

 sac involving the spermathecal sac which is mentioned by 

 the last-named aiithor. But the egg-sacs were evident one 

 on each side of the anterior end of the muscular part of the 

 spermathecal sac. b'ome filmy membranes, which I could 

 not map out, are doubtless the remains of the coclomie 

 chamber referred to by ^lichaelsen. These I refer to later. 



The accessory pouches ("Nebentaschen "), closely attachecJ 

 to the outward cud of the spermathecal sac, communicate,, 

 as it would appear, witli the exterior through the paired 

 orifices, described above as lying beliind the spermathecal 

 opening. I cannot recall any structure precisely similar 

 to tliese among the Oligochseta. They might conceivably 

 be the vestiges of sacs formerly containing copulatory setae, 

 such as do occur in tlie group. But this suggestion is- 



