516 The Philippine Journal of Science 1920 
first, third about one-third as long as the second; flagellum of 
about thirty joints, rather stout; secondary appendage very 
small, of two minute joints, shorter than the first joint of the 
primary flagellum. Second antenna about as long as the pe- 
duncle of the upper; flagellum of about six joints, the first being 
much longer than the others. First gnathopod with basal joint 
broad, ischium rounded on posterior side and covered with mi- 
nute setae; carpus slightly longer and broader than the propod; 
palm transverse, slightly convex. Second gnathopod with car- 
pus subtriangular, propod narrow, oval, palm very oblique, oc- 
cupying more than half the posterior margin of the propod, 
nearly straight, defined by one or two stout setules. First and 
second perseopods with the basal joint broadened, oval, greatest 
breadth about half the length. Fifth peraeopod with basal joint 
of moderate size, remaining joints slightly broadened. Third 
uropods, when fully developed, about three-fourths the length 
of body, peduncle elongated, outer branch elongated, of two very 
long joints, first somewhat longer than the second, inner branch 
very small. Telson cleft to the base, each lobe bearing a stout 
seta at about the middle of the lateral margin and another near 
the extremity, with a minute setule placed at the extremity 
nearer the median line. Length of body, about 8 millimeters. 
Color, whitish. 
Locality . — “From a well at Los Banos, Luzon. Collected by 
S. Lantican.” 
In addition to the specific diagnosis given above, the following 
further details may be useful. In general shape of the body the 
species resembles Niphargus ckilkensis and most of the other 
species of the genus, the body being long, slender, and with the 
side plates much shallower than their respective segments. The 
head is produced laterally between the bases of the upper and 
lower antennas into a distinct, rounded lobe. The pleon segments 
are not much produced downward, the first less so than the 
second and third ; their lower margins are convex, the postero- 
inferior angle being broadly rounded and provided with minute 
setules arising from small indentations or serrations. The dor- 
sal surface of the body is free from hairs or setae. 
The branchiae are regularly oval, thus differing in shape from 
those of N. chilkensis, which are broad at the base. The an- 
terior pairs are apparently smaller than the posterior. The 
length of the body of one specimen mounted on a micro-slide 
is about 8 millimeters, that of the upper antennae being about 
