2 o2 CRUSTACEA MALACOSTRACA. III. 



Mediterranean (Budde-Luud and other authors); Risso's statement (test. Cams) on its occurrence at 

 Nizza ought therefore to be considered as somewhat doubtful. Finally taken at Newport, Rhode Island, 

 U. S. (Richardson). 



Sub-Order Epicaridea. 



In the paper on the Isopoda, etc., from the German Plankton-Exped. (Ergebn. der Plankton- 

 Exp. Vol. II, G, c, 1895) I pointed out the importance of the structure of the types of the second 

 larval stage for the classification of the families (or sub-families, as I named them) of this division of 

 parasitic Isopoda. In 1887 Giard & Bonnier had divided the Epicaridea into seven families, one among 

 them being the Microniscidae. The genus Microniscus I discarded as too imperfectly known and treated 

 it with caution; of the other families I suppressed two, reducing three families to a single family, the 

 Cryptoniscidae, especially because in all three "families" the second larval stage shows rather close 

 relationship and differs much from those of the remaining three families. Finally I decribed and figured 

 twenty species of larvae in second stage of all four "subfamilies", pointing out a good number of 

 characters. 



In 1898 G. O. Sars showed that the genus Microniscus, consequently the family Microniscidse 

 Giard & Bonnier, must be cancelled, as the animals in question are "a transitory larval stage of Epica- 

 rida belonging to different families" (Account, II, p. 218); furthermore he adopted my division of the 

 Epicaridea into four families, yet without mentioning my paper; the only addition worth mentioning 

 he made as to this topic was to cancel the family Podaseonidae established by Giard & Bonnier a 

 few months after my above-named paper had been published. 



In the voluminous and valuable book: Contributions a L'Etude des Epicarides, 1900, J. Bonnier 

 attempted a new classification. He divided the Epicaridea into two groups: Cryptoniscinae and Bopy- 

 rinae, which may be acceptable chiefly for the reason, that in the Cryptoniscinae the male preserves 

 completely the external structure of body and appendages found in the second larval stage, while in 

 the Bopyrinae the male is quite different from that larval stage. But as strong differences are found 

 between the second larval stages of the Bopyridae and the Dajidae, and as the females of the Entonis- 

 cidae differ extremely from those of the Bopyridae or the Dajidae, it may be only a matter of opinion 

 whether the three families Bopyridae, Dajidae and Entoniscidae are united as a group opposed to the 

 Cryptoniscidae, or all four families are arranged as equivalent. Furthermore Bonnier divided his Crypt- 

 oniscinae into eight families, among which the unfortunate Microniscidae, but this classification is 

 extremely premature, being based mainly on the idea that parasites found on two different orders of 

 Crustacea cannot belong to the same family; this classification must be totally discarded. Finally he 

 divided the Bopyrinae into four families: Dajidae, Phryxidae, Bopyridae, and Entoniscidae; to the Phryx- 

 idae he referred forms living on the abdomen of the Deeapoda, and to the Bopyridae those inhabiting 

 the branchial cavity, but this classification, which he characterized as provisional, has no value, and 

 the two families named must be united. 



The material from our area is not large, comprising only thirteen species, belonging to three 



