4 PROCEEDINGS OF THE NATIONAL MUSEUM. VOL. XXXIY, 
If we want to include Callomysis as well as the Amblyops and 
Erythrops groups into this subfamily, we are to alter shghtly the 
above diagnosis of the Leptomysine as given by Norman, and put 
it the following way: 
Subfamily: Leptomysine. 
Outer uropods one-jointed, their outer margin setose. Gnathopods 
(second cormopods) conforming im general character of the endopo- 
dite to the maxillipeds (first cormopods). First true legs (third 
cormopods) similar to the following in general character, and not 
very greatly developed and longer than the latter. Male with all the 
pleopods well developed, and adapted for swimming; second to fifth 
pair biramose, and never resembling those of the female. Sometimes 
one of the branches of the fourth (rarely the third) pair modified 
jor sexual purposes, in being slightly lengthened and possessing pe- 
culiar setee on the terminal joints. 
~The following key of the genera of Leptomysinee mentioned above 
may be convenient for their identification. No complete revision of 
the subfamily is intended. 
KEY TO GENERA. 
a. Eyes rudimentary, lamelliform. Male pleopods very uniform, the first with 
inner branch rudimentary, the second to fifth with two subequal branches. 
Amblyops Sars and Pseudomma Sars. 
a’. Eyes not lamelliform, more or less globular. 
b'. Telson short, sometimes hardly longer than wide, always much less than 
twice as long as wide. Outer margin not spinous (or rarely so, in 
Huchatomera). Apex not cleft. Male pleopods very uniform, the second 
to fifth with two subequal branches. 
Erythrops Sars,” Parerythrops Sars,? Huchetomera Sars.¢ 
vb’. Telson longer, generally at least twice as long as wide. Outer margin 
always spinous. Apex entire or cleft. Male pleopods less uniform ; 
one branch of third or fourth pair generally longer than the other (the 
prolongation sometimes only caused by the presence of a terminal spine). 
c’. Pleopods of female rudimentary, simple. Outer or inner branch of 
fourth pleopods of male with tendency to become lengthened. 
d’. Outer margin of antennal scale setose, without distal spine. Outer 
branch of fourth pleopods of male with tendency to become length- 
ened, its terminal joints only slowly increasing in length, if at all. 
e’. Telson elongated, linguiform, apex pointed or rounded, not cleft. 
Three last joints of outer branch of fourth pleopods of male with- 
_ out setxe, but with three strong spines. Antennal scale very long, 
TATTOO Wei DO RTE Ce a Stee a eee Rng Leptomysis Sars.@ 
@Sars, Monogr. Mysid., I, 1870, p. 11; Norman, in Ann. Nat. Hist. (6), X, 
tSOZ aaa Se ; ; 
® Sars, Idem, p. 40. 
¢ Sars, Rep. Voy. Challenger, XIII, 1885, p. 211. 
@Sars, Monogr. Mysid., III, 1879, p. 29; Norman, Ann. Nat. Hist. (6), X, 
1892, p. 242, 
