POLYCH.^TA.— BENHAM. 153 



The number of chsetse in the first and second bundles as 

 well as the vertical length of the bundle are greater than in 

 the succeeding segments ; the length of the second bundle 

 being twice that of the sixth, but, in compensation, the 

 height of the torus has increased. 



There are two kinds of chaetse in the notopodium (PL xlviii., 

 fig. 41) — (a) long, brownish capilhforms, with a very narrow 

 flange and attenuate apex which is biserrulate (PI. xlviii.^ 

 fig. 44) ; and {b) much shorter, rather thinner, colourless, 

 biflanged bristles, whose apex is also very long, but without 

 serrulations ; the flange on one side is much wider than on 

 the other (PI. xlviii., fig. 45). These smaller chaetse lie 

 anteriorly to the longer. 



I counted in two bundles 20 of the longer and 12 of the 

 shorter sort. 



The hooks (PI. xlviii., figs. 42-43) have a nearly straight 

 shaft with a long terminal tooth, Avith three or four suc- 

 cessively smaller teeth on its back, and the usual tuft of 

 delicate filaments projecting upwards in front. 



Remarks. — There is, I think, reason to suppose that 

 Praxilla abyssorum, M'Intosh, is identical with this species. 

 The figures in the " Challenger " Report (PI. xlvi., figs. 10, 11) 

 certainly disagree with the genus Praxilla in the form of the 

 hea^l and in other details. The figure is not very detailed, 

 owing possibly to the state of contraction of the worm, but 

 it shows the biannulate peristomium and the horizontal 

 furrow on its side. It is true that MTntosh states that the 

 uncini do not begin till the 5th segment ; that again is possibly 

 due to its state of preservation, for the tori in these anterior 

 segments are quite short and the hooks few. The figure of the 

 hooks, however, agrees precisely with that found in the present 

 species. It appears, moreover, that he found two kinds of 

 dorsal chsetae in the first four segments at any rate, for he 

 writes : — " Some of the bristles are furnished with a distinct 

 wing, while others are simple slender tapering structures." 

 Another fact weighs with me, viz., that the worm was 

 obtained in nearly the same region, " midway between the 

 Antarctic region and Australia, in 1950 fathoms." 



The form of the head, as well as certain other features, 

 agree with Ehlers' account^ of Asychis (Maldane) amphiglypta 

 from South Georgia. At first he placed it in the genus Mal- 

 dane, but in his account of the New Zealand Polychsetes^ 

 it was included in the genus Asychis. 



1. Ehlers — Polychseten Hamburger mai^alhaenische Sammelreise, Ham- 

 burg, 1897, p. IFQ. 



2. Ehlers — Neusceland. Annelid., 1907, p. 2fi. 



