ENTOZOIC COPEPOD FROM JAPAN. 2S 
the name for a new genus of Muscide, in the group of Diptera*. 
Then, in 1874, Dr. R. Kossmann published his account of the 
Copepod Hersilia under the name of Clausidium testudo. In 
1886 Professor Heller met with it in the branchial cavity of 
Callianassa. Since then several other authors have investigated 
the parasite under the name Hersilia, with the result that the 
family name, in 1888, became Hersiliide@. The consequence is that 
there exist four genera with the same name, two of which give 
the name to the family Hersiliide. Such an occurrence is 
always the source of much confusion; but in this cage the 
possibility of error is increased by the fact that they are all 
Arthropoda. To avoid any further misunderstanding, I have been 
advised by Dr. D. Sharp and Mr. C. Warburton, of Cambridge, 
to entirely remove the names “‘ Herstliide”’ and “ Hersilia” from 
the order Copepoda. I propose, therefore, to substitute for 
Hersilide the family name Clausidiide, aud for Hersilia the 
generic name Claustdiwm as proposed and used by Kossmann in 
1874. It seems best to thus adopt the name used by Kossmann, 
instead of introducing a new one, as I had at first intended to do. 
I shall use these names throughout the paper, except of course 
where I quote other writers, m which case I shall give those used 
by them. 
In spite of the fact that several authors have paid special 
attention to it, the genus “ Hersziia” is still looked upon as 
aberrant, and the opinions as to its affinities differ widely. 
Kossmann, as we see, calls it Clausidium, and claims for it 
relationship with the Siphonostomes—Artotrogus and Astero- 
cheres. Others ally it to the Peltidiide. Claus and Heller 
claim (and, so far as I can judge, are justified in so doing) that 
the “ Hersiliide” are a family of Copepods, distinct alike from the 
Siphonostomide and from the Peltidide ; while Milne- Edwards + 
admits the difficulty in classifying them. He says they seem to 
have some analogy with the Sapphirinide and Peltidide, but 
that they also approach the Argulide in the general form of the 
body ; our knowledge of them being so incomplete, he is unable 
to determine with certainty their place in the natural system of 
classification. 
* « Hersilia (Robineau-Desvoidy),” Hist. Nat. Diptéres Env. Paris, i. p. 499, 
1863: Muscide. 
+ Hist. Nat. Crust. ii., 1840. 
