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of this uncertainty are partly, that the males of too few forms are known, partly — and 
particularly — that the metamorphosis of numerous genera among the old families and of 
the more abnormal forms is entirely unknown, and that the structure of the mouth in the 
adults as well as in the larve is often badly studied, etc. A revision of the classification 
of the parasitic Copepoda would be most desirable and ought to be based upon a thorough 
study of the external structure of both sexes, and upon numerous new data which throw light 
ou the post-embryonic development; that a representation of the internal structure of numerous 
types would be excellent, goes without saying, but even without undertaking this gigantic 
work such a revision as the above-mentioned would be exceedingly useful. However, as 
such a work does not exist, I do not see that it can be of much use to discuss the relation- 
ship of the Choniostomatide and their place in the system more in detail, so [ will content 
myself with some few remarks. 
The last detailed systematic arrangement of the parasitic Copepoda was undertaken 
by A. GersTarcKker in » Bronn’s Klassen und Ordn. des Thier-Reichs, fiinfter Band, erste 
Abth.« p. 721—729, and this part was published about 1870. Perhaps we might also 
mention the more condensed grouping in »C. Craus: Grundziige der Zoologie, B. I, 1880, 
p. 554—58,« as it is set up by the author who has also gained great distinction in this 
domain of carcinology. By studying these treatments and several papers on special groups, 
I have found out that the family Choniostomatide stands far apart from all hitherto established 
families, except Lernzeopodidx, from which, however, it also ditfers considerably. If Salensky 
in his often mentioned paper means that Spheronella comes nearest to Lerneidee, because he 
thinks that in the structure of the mouth and in the form and position of the maxille and 
the maxillipeds, it resembles Lernea branchialis in the pairing stage, we admit indeed that 
the resemblance in the structure of the mouth is doubtless very striking, but in other respects 
the various larval stages of Lernea and Pennella differ widely from the larvee and pupz of 
Choniostomatide, and the subsequent development of the two genera of Lernzide, as we 
know, differs so thoroughly from that of the Choniostomatidee, moreover, the structure and 
egg-laying of the female of Lernea is so exceedingly different from these features in our 
family, that a closer relationship is entirely out of the question: in my opinion Lerneide 
and Choniostomatide stand very far from each other. But undeniably it stands even farther 
apart from Herpyllobiide, though Giard and Bonnier have attempted to unite it with this 
most remarkable family, which differs widely from all other parasitic Copepoda. They do so 
by establishing a new family: Spheronellide, which they subdivide into Choniostomatinz 
and Herpyllobiine. This peculiar classification I have criticised at length in my general 
historical view (p. 15—21), to which I refer. The same two authors, in their earlier work, 
published in 1889, say that Choniostomatidse comes nearest to Chondracanthide, Lernzeopodidee 
and Ascomyzontide. The first and the last of the families in several respects — e. g. in 
the structure of the mouth — deviate so much from Choniostomatide, that any closer 
relationship is out of the question; indeed our family stands widely apart from both, 
