384 W. BLAXLAND BENHAM. 



length then up to Somite xii^ then decrease for a few 

 somiteSj and retain a normal length to the end of the body. 

 In one or two specimens I noted that the dorsal chsetge of 

 Somite vi consisted only of crochets, one on one side, two on 

 the other side ; in Somite vii there were two furcates and a short 

 capilliform, only slightly exceeding them in length. It is, 

 perhaps, needless to remark that the dorsal bundles are absent 

 in the first five somites. 



A comparison of my figure of these dorsal chsetse with those 

 of Vejdovsky ^ shows that the shape of the chaetse does not 

 agree with those of either of the species, N. barb at a, N. 

 elinguis, or N. josinse, described by him. 



In the last species, however, the dorsal bundles do contain 

 crochets in addition to capilliforms ; but not only do these 

 differ from those of N. heterochseta in position of the 

 " node," but also in the fact that two of them and two capilli- 

 form exist in a bundle, and in the relative size of the two. 



Another point of difference — if the above be not sufficient — 

 is the presence of eyes in my species, whereas they are absent 

 in N. josinse. 



The ventral chsetse (fig. 3) are of the usual Naid shape; 

 usually there are four in a bundle, rarely three or five. 

 Those of Somites ii, iii, iv, and v differ slightly from the 

 remainder in that the distal prong is rather longer than the 

 proximal; whilst in the normal chsetse the two prongs are, as 

 nearly as I can make out, equal in length, though the proximal 

 prong is distinctly the stronger. 



The blood is yellow, and the connections between the 

 dorsal and ventral trunks (fig. 1) are peculiar. The two 

 lateral branches into which the dorsal vessel divides in the 

 prostomium, in front of the brain, unite in Somite v to 

 form the ventral trunk ; these are connected with the dorsal 

 trunk by four pairs of vessels, each of which branches more 

 or less irregularly, as will be understood better by a reference 

 to the figure than by a description.^ The arrangement is 



1 ' System unci Morphologic d. Oligocbiitcii,' pi. ii, Cgs. 18, 19, 26. 



* These branches arc acconipauied bj irregular patches of browu pigment 



