18 



d'antennes, meine structure de l'appareil buccal avec la ventouse si sp6ciale et les appendices 

 transformed en stylets, meme disposition des membres thoraciques, etc. 



Les jeunes individus surtout presentent une ressemblance extraordinaire et indiquent 

 nettement la parente des deux groupes. 



Mais il est un caractere du male sur lequel nous d6sirons particulierement attirer 

 l'attention, parce qu'il est tres exceptionnel et qu'on ne le retrouve dans aucune autre 

 famille de Cop6podes, en dehors des Ghoniostomatince et des Herpyllobiince. 



Les canaux excreteurs des glandes genitales males debouchent dans la partie cepha- 

 lique de V animal et dans le voisinage de la bouche«. 



Let us examine this a little more closely. Though the authors think that the 

 larvae in particular show »une ressemblance extraordinaire*, we find that these larvae, which 

 indeed may be said to be in the first Cyclops-stage , resemble each other less than the 

 larvae 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 larvae of a PJiizorhina 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 larvae of the last-mentioned group and e. g. of a larva 

 of Pennella. The maxillae of the two groups deviate much from each other in shape and 

 position etc. Several great differences between the males of Choniostomatidae and of Her- 

 pyllobiidae 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 degradation, toute comparaison peut sembler 

 d6pourvue de valeur«. In the former type, the Choniostomatidae, the female possesses at 

 least the antennulse, a well-developed mouth with mandibles, maxillulae and maxillae; in 

 the latter, the Herpyllobiidae, 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 (Rhizo- 

 rhina) which is found in the body of the host, and which has a most curious, hitherto 

 unexplained development (comp. my essay about PJiizorhina). 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 Herpyllobiidae. The authors substantiate their opinion in these words: »Ce 

 caractere, tellement extraordinaire que nous ne l'avions signale qu'avec reserve dans notre 

 etude sur Aspidoecia et dans nos recherches plus r6centes sur Salenshya, Hansex l'a mis 



