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dantennes, méme structure de l'appareil buccal avec la ventouse si spéciale et les appendices 
transformés en stylets, méme disposition des membres thoraciques, etc. 
Les jeunes individus surtout présentent une ressemblance extraordinaire et indiquent 
nettement la parenté des deux groupes. 
Mais il est un caractére du male sur lequel nous désirons particuliérement attirer 
l'attention, parce qu il est trés exceptionnel et qu’on ne le retrouve dans aucune autre 
famille de Copépodes, en dehors des Choniostomatine et des Herpyllobiine. 
Les canaux excréteurs des glandes génitales males débouchent dans la partie cépha- 
lique de Vanimal et dans le voisinage de la bouche«. 
Let us examine this a little more closely. Though the authors think that the 
larve in particular show »une ressemblance extraordinaire«, we find that these larve, which 
indeed may be said to be in the first Cyclops-stage, resemble each other less than the 
larve of a Choniostomatid and of an Achtheres respectively, according to the illustration 
given by Claus (Zeitschrift wissensch. Zoologie B. XI, Taf. XXIII, fig. 5). At any rate, 
the likeness between the mouths of the larve of a Rhizorhina and of that of a Choni- 
ostomatid is not so great as the authors seem to think, and it is certainly much smaller 
than that between the mouth of a larve of the last-mentioned group and e. g. of a larva 
of Pennella. The maxille of the two groups deviate much from each other in shape and 
position ete. Several great differences between the males of Choniostomatide and of Her- 
pyllobiide have been pointed out above, and we shall soon mention more. The differences 
between the adult females also seem to be so great that we are struck by the astonishing 
boldness of the assertion that: »en raison de la dégradation, toute comparaison peut sembler 
dépourvue de valeur«. In the former type, the Choniostomatide, the female possesses at 
least the antennule, a well-developed mouth with mandibles, maxillule and maxille; in 
the latter, the Herpyllobiide, the body has no vestige of these organs or of any limbs, and 
in the three genera which are examined so thoroughly, that our knowledge about their 
nutrition is perfectly reliable, we know that it takes place through a large mysterious body 
(in Herpyllobius and Silenium) or through an equally mysterious tubular system (hizo- 
yhina) which is found in the body of the host, and which has a most curious, hitherto 
unexplained development (comp. my essay about Rhizorhina). Indeed, I can find no other 
likeness between the females of these families than the small size of their bodies, their sub- 
globular or oval form, and their two genital apertures, and as this last character seems 
to be common to all parasitic Copepoda, we might as well pass it over. 
But still more objectionable is the statement printed in italics, that in the males 
of both families the genital aperture is found on the head near the mouth. I shall begin 
by speaking of Herpyllobiidee. The authors substantiate their opinion in these words: »Ce 
caractére, tellement extraordinaire que nous ne l’avions signalé qu’avec réserve dans notre 
étude sur Aspidoecia et dans nos recherches plus récentes sur Salenskya, Hansen l’a mis 
