50 AUSTRALASIAN ANTARCTIC EXPEDITION. 



able from Lagisca by the absence of the prostomial frontal lobes or " peaks ;" the dorsal 

 chaetse are generally smooth or very feebly striated ; the ventrals unidentate in even in 

 the young. Therefore, he believes that to unite the two genera would be premature. 



But is the statement of differences altogether correct ? For Ehlers describes the 

 presence of these " peaks " to two species, Hermadion ambiguum and H . molluscum 

 (1897, p. 16); they are present in H. rouchi. It is true that these peaks are absent in 

 the type species, H. magalhaensis Kinberg, as well as in his H. longicinatum and in 

 H. kerguelensis Mclntosh (1885), which according to Fauvel are synonymous. On the 

 other hand, although typically present in Lagisca, they may be absent (see L. Jeffreys ii 

 Mclntosh, for instance). It seems as if there ought to be a great deal of shifting of these 

 species from one genus to the other, if we accept Fauvel's dictum. 



As to the dorsal chaetse, it appears that in young stages of H. rouchi, at any rate, 

 as well as in other species, the dorsal chsetae do have striations, that is fine pectinated 

 frills or combs, whereas in the older chsetse, the longer ones, they are less distinctly 

 marked. It may be that this is due to wearing away of the frills owing to use. And a 

 similar explanation may perhaps be given of the absence of a sub-apical tooth in the 

 ventral chsetse. For although this is generally absent, yet it does occur in the shorter 

 younger chsetse, or in others its place is taken by a " step," in this position. 



It appears then that the distinctions between the two genera Lagisca and Herma- 

 dion do not exist. They are identical. 



A further question has been raised as to whether or not there is any real distinction 

 between the genera Hermadion and Har^othjc. If we review the various oligomeric 

 forms, it appears that Harmothoe has its dorsum entirely covered by the elytra ; that 

 none of the posterior segments remain uncovered, or at most only two or three. Whereas 

 in Hermadion, several, up to a dozen or more, are exposed in large forms. It is true 

 that Willey has ascribed to Harmothoe spinosa an individual which he regards as a 

 variety and calls " lagiscoides ," partly because of the conical tubercles on the elytra, 

 and this one individual has 6 naked segments at the hinder end. But more information 

 *s needed to convince me that the individual is a variety of Harmothos spinosa. 



Yet, because of this variety, Willey proposed an addition to the generic diagnosis 

 of Harmothce, which would eliminate the only remaining constant difference between 

 it and Hermadion, and so comes to the conclusion that all three genera are synonymous. 



For the present, I am of opinion that it would be well to retain the distinction 

 between Harmothoe and Hermadion. 

 Localities . 



Commonwealth Bay, Station 1, 350-400 fathoms (six, colourless). 

 Station 10, 325 fathoms (one juvenile, colourless). 

 Station 12, 110 fathoms (one juvenile, coloured). 

 No data (one coloured and one uncoloured, juvenile). 



Distribution. Marguerite Bay, ile Adelaide (Gravier), Kaiser Wilhelm II Land 

 (Ehlers). 



