Hexham. — Some New Zealand Polychaetes. 167 



it is purely cuticular. In one case at least I note that it surrounds the apex 

 of the hook. 



Distribution. — New Zealand, Chatham Islands, Kermadec Islands. 



Remarks. — I have described this worm at some length, in spite of the clear 

 account given by Ehlers, because in one or two points that account seems 

 to me to require extension. He described two species — F. lingulata and 

 F. semiannulata — both from the Chatham Islands, and the latter founded 

 on a single individual. And the differences between these two seem to me 

 from a comparison of a large series of specimens from various localities 

 to be individual rather than specific. In the first place, though he does 

 not refer to this explicitly, the presence of the median dorsal tentacle, or 

 Ll lingula,"' is not denied for F. semiannulata ; no mention is made of it, 

 and one may therefore presume its absence. The slight differences that 

 lie notes between the general form of the body and the condition of the 

 head are, in my opinion, due to differences in the state of contraction — 

 that is, the head as described for F. semiannulata is retracted to such an 

 extent that in fig. 7 the bases of the peristomial chaetae are apparently 

 within the projecting margin of the next segment, and the body as de- 

 scribed for F. lingulata is much distended with food. I have shown above 

 that this naturally makes a considerable difference in shape and in the 

 clarity of the segmentation. But in his summary at the end of his account 

 of F. semiannulata on p. 50 Ehlers lays more stress on the difference in the 

 ventral chaetae, for he found two in each bundle in F. lingulata, and onlv 

 one in the other species. In the latter it is accompanied by capillaries, 

 which he did not find in F. semiannulata, and there is some difference in the 

 angle formed by the claw on the shaft; the hook is said to be " far pro- 

 jecting," and the specific name apparently refers to the pseudo-articulation 

 of the hook. 



In addition to these specimens from the Kermadec Islands, I have a 

 large number collected from various parts of the coast of New Zealand 

 and from the Chatham Islands (whence a ... 



Professor Ehlers obtained both his \\ -^ ., „ „ /// 



species). Now, all these agree in VA ^\m\\\\\\\\\ lllliliflflf}/! / 

 possessing a single hook (except occa- ^^\ \\\\\\\\\\\\\\ I III //////////// III 



sionally here and there in a worm, \V ^^^^mJ\\uMlu\uM- HI 



when two may be present) enclosed in \\ p^^^^ fu] 



a sheath and of the form figured for — --\i Villi 1/1 



F . semiannulata, but accompanied by <£- — ^[j^^k ill/f / 



capillary bristles ; and also in the >| ^%r ut^^ / 



presence of a median dorsal tentacle, \ ^P^ / 



or " lingula." w, f 



Some specimens from Auckland 

 are particularly instructive : they are FlG - 1 -~ A specimen from Auckland. 



i - .j t, i " The peristomium has been slit 



much contracted, having been pre- ' . ^ + „„ 



p r up, so as to expose the ten- 



served in strong alcohol; the head fcacular platform and the "lingula." 



is withdrawn, and the gut protrudes a, tentacles ; b, peristomial chaetae 



through the mouth. At first I was ( cut short ) "> , \ peristomium ; 



ii , n j ,-i j- i d, tentacular platform ; e, lin- 



unable to find the median tentacle, ' ,„ „ 



•itt • • i gula. 



until 1 slit up the peristomium and re- 

 flected the chaetae of the crown ; then it is recognizable, though relatively 

 shorter than in uncontracted specimens (fig. 7). These Auckland specimens 

 I had originally labelled " F. semiannulata, ," as they agreed so closely with 

 the general account of that species given by Ehlers ; but I find here, too, 



