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consists in his indicating new a locality for Choniostoma on the other side of Nova Zemblia 

 opposite to mine (the Kara Sea), and that an otherwise very deserving author has committed 

 a most peculiar mistake. That is all; whether I ought to have mentioned the subject is a 

 matter of opinion; at the time I thought it might as well be left out. 



I shall pass over several other remarks which might call for censure, and take up 

 some hypotheses set forth rather hesitatingly by the authors, p. 352 — 53. After having 

 declared themselves at a loss to understand that a Choniostoma with its ovisacs can cause 

 a swelling in the carapace of a Hippolyte entirely resembling that which is produced by 

 Gyge Hippolytes, t\\vj write: »I1 nous parait beaucoup plus vraisemblable d'admettre que le 

 Oopepode a infeste" les Hippolytes deja parasites par les Gyge, et qti'il supplante les Epicarides 

 on tout au morns profite pour se loger de la d6formation produite par ces derniers«. To 

 this conclusion they add a doubt which I think rather irrelevant, and say further: »N6au- 

 moins en rapprochant l'6thologie d'Aspidoecia de celle de Choniostoma, il nous semble 

 bien probable qu'il existe un rapport, soit de parasitisme, soit de mutualisme, entre ces 

 parasites et les Epicarides des genres Aspidophryxus et Gyge*-. However, they go still 

 further. They have found a genus of Epicaridea, Podascon G. and B., on a species of the 

 genus Ampelisca, and Salensky has found numerous examples of a Sphceronella in all stages 

 on an Amphipod of an altogether different family. Here we should think it would be rather 

 difficult to establish a connection between the Epicaridea (Podascon) and the Ohoniostomatidse 

 (Sphceronella), which live »exactementdans les memes conditions «; nevertheless they continue: 

 »on pent se demander s'il n'a pas exists autrefois entre ces deux groupes de parasites des 

 rapports analogues a ceux que nous avons cherche" a demontrer entre les autres Choniosto- 

 matides (Aspidoecia et Choniostoma) et certains Epicarides«. With the word »autrefois« 

 the authors resort to the past, but it will be impossible in a case like the present one to 

 gain any perfect or imperfect knowledge concerning the former state of things. We confess 

 that this invention would be ingenious if — as sometimes happens where an excellent thing 

 is carried to an extreme — it had not overstepped the limit and become ridiculous. 



My experience, which is based on very extensive researches, enables me to declare 

 that, as far as the present time is concerned, these hypotheses, which the authors repeat 

 with additional remarks in two later papers, are entirely destitute of foundation. 



Of infested Isopoda this work mentions four examples of three species with three species 

 of Sphceronella ; ofCumacea with parasites in the marsupium twenty-four examples belonging 

 to six species (the parasites belong to five species), and of these six species I have examined 

 several hundred specimens, in order to find those that were infested. Of two species of 

 Cumacea seventy -three instances were found with (two species of) Homoeoscelis under the 

 carapace; finally, one hundred and forty examples of Amphipoda (belonging to twenty- eight 

 species) were found and proved to be infested with twenty-eight species of Spliceronella and 

 Stenotocheres. Of these twenty eight species of Amphipoda I have examined several thousand 

 specimens. So the result is, that of all three orders together I have seen about two hundred 



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