128 "TERRA XOVA" EXPEDITIOISr. 



<-inuuiuiiicatinii witli tiu' luiiu'ii of the rliyiK'hodieuni. The figures giveu. liowcvur, 

 iU'L' not altogether couviuciiig ; and on re-examining the material (which is not 

 coiLspicuouslv well preserved), I have formed the conclusion that the "am])ull;o" 

 are to a certain extent artificial results of the contraction of the wall of the 

 rhynchodpeum. They are, in fact, a kiml of " hernia " of the lining epithelium, 

 which is here and there pushed outwards hetween the muscles, thus forming minute 

 diverticula still in communication with the main cavity of the rhynchodajum. They 

 do not occur in all the series of sections examined, and are not, therefore, an 

 essential feature of the species. Moreover, their outer communications with the 

 l)lood-sinus are, I believe, imaginary. In no case have 1 detected any actual 

 opening, and though they sometimes come very near to the surface, I believe that 

 this appearance is entirely due to artificial causes. 



Having already stated my conviction that Liiieii.s Innisi'm and l-lmmlia innnicfti 

 are synonymous with L. roiTiu/atus, I may perhaps be permitted further to achl that I 

 feel some doul)t as to whether Cerebratulus cliarcufi. .b)ubin, should not come under 

 the same category. The author's description (I'JOH) does not appear to me to show 

 an\" verv satisfactory grounds for its separation ; no description or figures of its internal 

 anatomv are given, and the main points upon whidi the distinction of the species 

 is based are (1) the marked flattening of the posterior end of the body : (2) certain 

 verv va"ue features of colour : and (;3) the "reat length and attenuation of the head. 

 Now (1) the flattening of the l)ody, as I have attempted to show above, occurs in 

 specimens which I cannot regard as other than T^. ravntgafUK ; {'1) colour, in spirit- 

 preserved material, can hardly be said to ha\e any importance at all. being often 

 affected \t\ the pigments of other siwcimens, &c., whicli nia\' have l)een immersed 

 ill tlie same spirit : while (;!) the comparati\(' length of tlie head, mouth, itc, \n 

 these worms is a matter obviousU' dependent upon the gi'owtli of the indisidual 

 and the mode of fixation or preservation employed, ami may lie extremely variable 

 in preserved specimens of the same species. 



Taking all these facts into consideration, I think llie e\idence points to the 

 conclusion that in all fV)ur cases (Lineus cornujnfiis, Liintis hanveni, ('frrbrafii/ii.s 

 fl/iirciifl. and Kit/ii)Iia jiinnutti) we are dealing with one and the same species, and tliat 

 this is the form originally desciibed by M'Intosh (1S7()) under the name of Lunns 



Distribution. 



By the inclusion of the several species above-nu'utioned in the synonymy of 

 L. coiriii/iifHs. the range of the latter is seen to extend to the western as well as the 

 eastern side of the subantarctic regions. The specimens determined by M. Joubiu as 

 Cerebrattihii^ corrmitUus and C. Charcot i came from Booth-Waudel Island. I have also 

 to add that some immature specimens brought from C^umberland Bay, Boutli Georgia, 

 by the late Major G. E. H. Barrett-Hamilton's Expedition, 1913-1914, belong, in 



