2 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxxiv. 



The present specimen agrees well with the one mentioned by the 

 writer among the Hawaiian Schizopods. Its length (difficult to 

 measure, since the specimen is doubled up) is about 55 mm. It 

 differs from the typical (adult) Gnathophausia gigas in the stronger 

 development of the branchiostegal, infero-lateral, and postero-dorsal 

 spines; the branchiostegal spines are even stronger than in the Ha- 

 waiian specimen. Besides, the supraocular is distinctly larger than 

 the antennal. The outer margin of the antennal scale has five distinct 

 teeth, while the type has only four, and the Hawaiian specimen has 

 also four, of which the last one is very small. The rostrum is longer 

 than in the Hawaiian individual; in the present specimen the part 

 in front of tke ocular spines is distinctly longer than the rest of the 

 carapace, including the posterior spine, while in the one from Hawaii 

 it is about as long as the rest of the carapace without the posterior 

 spine. All these minor differences apparently are due to age. 



Family MYSID.E Dana. 



Subfamily LEPTOMYSINJE INorman, 1892. 



The division of the family Mysidae into subfamilies seems quite 

 necessary on account of the large number of genera of very various 

 type contained in it. The subfamilies created by Norman a are chiefly 

 framed with reference to the British forms, and thus it is some- 

 times hard to assign foreign genera and species to their proper place. 



According to Norman, the following features are characteristic 

 for this subfamily: 



Outer uropods one- jointed, their outer margin setose. Gnathopods 

 (= second maxillipeds or second cormopods) conforming in general 

 character of the endopodite to the maxillipeds ( = first maxillipeds 

 or first cormopods) . First true legs (= third cormopods) similar to 

 the following in general character, and not very greatly developed 

 and larger than the latter. Male with all pleopods greatly developed 

 and adapted for swimming, second to fifth pair biramose, cdl branches 

 multiarticulate and setose, the outer branch of fourth, and sometimes 

 also of third modified for sexual purposes, but the modification only 

 extending to a slight lengthening of the limb and a change in the 

 character of the setce of the terminal joints. 



This diagnosis does not exactly apply to some forms, not treated 

 lyy Norman, which clearly ought to be placed here, while it apparently 

 fits others, which are more widely different in other characters. 



Boreomysis G. O. Sars, & for instance, although answering fairly 

 well to the above diagnosis, differs at once in the presence of seven 



«Ann. Nat. Hist. (G), X, 1802, p. 147, 

 & Monogr. Mysid., Ill, 1879, p. 8. 



