I. The Order MYSIDACEA. 



In 1883 J. E. V. Boas divided the Schizopoda into two orders, the Euphausiacea and 

 the Mysidacea, and the latter again into two suborders, Lophogastrida and Mysida ; this classi- 

 fication has been adopted by me in various papers and it is followed here. In his "Challenger" 

 work (Report, Vol. XIII, 1885) G. O Sars divided the Schizopoda into four families: Lopho- 

 gastridae, Eucopiidae, Euphausiidae and Mysidae, the two first-named families together answering 

 to the suborder Lophogastrida Boas, and the last-named family identical with the suborder 

 Mysida Boas. Sars, whose papers have furthered our know r ledge of the present order more 

 than the contributions of all other authors taken together, never attempted to divide his Mysidae 

 into subfamilies or groups. 



In 1882 Czerniavsky (Monographia Mysidarum imprimis Imperii Rossici, 1882 — 87) divided 

 the Schizopoda into six families : Nebalidae, Euphausidae, Lophogastridae, Petalophthalmicla-, 

 Mysidae and Chalaraspidae, in reality a most unfortunate classification, but it may be added that 

 the Petalophthalmidae, as to which only a poor preliminary note had been published, and the 

 Mysidae are accepted here. The family Mysidae he divided into six subfamilies, of which only 

 one, the Mysidellinae, is accepted; the names of two other subfamilies established by him, the 

 Siriellinae and the Mysinae, are adopted here, but these subfamilies are circumscribed in a very 

 different way and consequently their contents are partly very different ; his three remaining 

 subfamilies are discarded. Furthermore he established many new genera and subgenera, a good 

 deal of which are still-born. The author had a proportionately small material, and even sometimes 

 he established genera or subgenera on more or less significant imperfections or errors in descriptions 

 or figures of earlier authors, for instance Arctomysis Czern. as different from Boreomysis G. O. 

 Sars on a small error in Kröyer's description of the number of the "tarsal" joints in Mysis 

 (Boreomysis) arctica Kr. The work contains an excellent bibliography and an enumeration of 

 all species established, but in all other respects it is somewhat poor, especially as the author 

 ought to have used the two main papers of G. O. Sars (Monographi over de ved Norges 

 Kyster forekommende Mysider, 1870 — 79, and Middelhavets Mysider, 1877) as models of his 

 own task. 



In 1892 A. M. Nörman (On British Mysidae: Ann. Mag. Nat. Hist. Ser. 6, Vol. 10) 

 divided the members of the family named inhabiting or possibly inhabiting the British seas into 

 seven subfamilies, viz. Siriellinae, Gastrosaccinae, Heteromysinae, Leptomysinae, Mysinae, Stilomysinse 



