410 
ZOOLOGY OF THE FAR EAST. 
Antennal scale (PI. XV, fig. 7) narrowty lanceolate in shape, about seven times as 
long as broad, two-jointed, distal joint one-seventh of the entire length of the scale, 
margin of the .scale .setose all round ; the .scale extends for f of its length beyond its 
own peduncle and one-third of its length beyond the antennular peduncle ; the 
.second joint of the antennular peduncle is longer than the third and there is a pro- 
minent spine on the outer corner of the basal joint from which the scale springs. 
Labrum without a spine ; masticatory lobes well developed on the second, third 
and fourth joints of the endopods of the first thoracic limbs; tarsus of the third to 
the eighth thoracic limbs four-jointed. 
First, .second and fifth pleopods of the male, as in the female, consisting of a 
single- jointed uniramous plate. 
Third pleopod of the male, (PI. X\', fig. 9) biramous, inner ramus a single- jointed 
plate, outer ramus nearly three times as long as the inner ramus, three-jointed, first 
joint twice as long as the inner ramus, with three long setae on the outer margin 
near the distal end, .second and third joints together about one-third of the first 
joint the second joint slightly the longer and having a single seta on its outer distal 
corner, third joint terminated by a single long seta, longer than the third joint but 
shorter than the second and third joints combined. 
Fourth pleopod of the male (PI. XV, fig. 10) very long, reaching to the posterior 
end of the telson, biramous, inner branch a single-jointed plate, outer branch four 
times as long as the inner, four-jointed, the first joint twice as long as the inner 
ramus, the second joint about half as long as the first, third joint slightly shorter 
than the second with a single very strong plumose spine on the outer corner, which 
is nearly twice as long as the joint and, extends well beyond the spines on the 
terminal joint, latter quite short and terminated by two long .spines four times as 
long as the joint. 
Length of adult male, 5 mm. 
This interesting little species is apparently very abundant in the Tale Sap, more 
abundant in the inner lake than in the outer. In the inner lake the water is quite 
fresh, whereas in the outer lake the corrected .specific gravity of the water at the 
time these specimens were taken was 1-00425. 
The species-is therefore a true lacustrine form. It is readily distinguishable by 
the .sj^inules on the carapace, the form of the telson and the character of the male 
pleopods. It is very closel}' allied to the Indian Potamomysis assimilis which lives 
in very similar habitats, but differs in the form of the telson, and particularly in 
having the third pleopod of the male rudimentary and of the same form as in 
the female. 
Genus Neomysis, Czerniavsky. 
Ncomysis nigra, Xakazawa. ^ 
(PI. XV, figs. 5-6.) 
N. nigra, Nakazawa, 1910, p. 248, pi. viii, figs. 3, 17, 30. 
Locality : — Whangpoo River, 5-10 miles below Shanghai, 5^-7^ metres, 10. xii. 15, 
