52 BiNiographical Notices. 



ratory of Wimereux) resolved to combine their efforts in order to 

 prepare a monograph of the Bopj'ride Crustacea or Epicarides ; but 

 the difficulties inherent in the work proved to be greater than they 

 expected, and they have thoxight it best to publish as much as they 

 could at once work up, without waiting to finish what would require 

 years of labour for its completion. Here, therefore, we have the 

 history of only two of the groups into which the Epicarides are 

 divided, the subfamily loninre and the Entoniscida). 



The treatment of the subject which the authors have adopted is as 

 follows : — Selecting as the type of the group to be discussed some 

 species which they have had the opportunity of examining 

 thoroughly, they describe in detail its external and internal struc- 

 ture, notice its mode of occurrence, its development and mode of 

 life, and finally its relationships, the last-named subject leading to 

 a submonographic revision of the genera and species referred to the 

 group of which it is taken as the representative. Thus in the first 

 section of their memoir, which is devoted to the loninge, they take 

 as the type a species described under the name of Oepon elegans^, 

 parasitic upon PUumnus hirtellus at Wimereux, and following the 

 mode of treatment above indicated, furnish full particulars of the 

 structure and natural history of the creature, with occasional refer- 

 ences to the writings of other authors who have noticed members of 

 the same group. This special description is followed by a syste- 

 matic summary, giving a list, with synonyms, of all the genera and 

 species of the subfamily loninae, with characters of the genera and 

 frequentl}' of the species, and notes on the habits and mode of occur- 

 rence of the latter. For the Entoniscidse the type selected is the 

 parasite of the common Shore-Crab, described by Giard under the 

 name of Entoniscns mcenadis, but now placed by the aiithors in a 

 new genus, Portumon. In their treatment of this group the authors, 

 while specially describing the form selected as illustrating it, refer 

 more to characters and peculiarities presented by other forms, and, 

 especially in the section on the ethology of the parasite, they go into 

 various most interesting questions connected with the history of 

 these crustacean parasites, and with the phenomena of parasitism in 

 general. 



We are quite conscious that in what has been said above we have 

 given a very imperfect account of a most excellent and exceedingly 

 important work, but to do more would have carried us to a much 

 greater length, and we can only hope that the few lines which we 

 have been able to devote to it will suffice to indicate to those inter- 

 ested in the subject the rich store of material which is here opened 

 up to them. So far as one can judge without special study of the 

 objects, the authors' work has been most admirably done ; in fact, 

 in some respects, in its thoroughness and evident truthfulness espe- 

 cially, it reminds one not a little of the work of the great English 

 naturalist whose loss we all still regret so heartily. It is, in fact, a 

 book that Charles Darwin would have welcomed with open arms. 



Forming the fifth volume of the " Travaux de I'lnstitut zoologique 

 de Lille et du Laboratoire de Zoologie maritime de Wimereux,'' its 



