Curb ToN.—On some Subterranean Crustacea. 89 
I have now to add another obtained from the same well as the other 
Subterranean Crustacea that I have described. 
Genus Phreatoicus, (novum). 
Body long, sub-cylindrical, laterally compressed. Upper antenna 
short, lower long, with flagellum. Mandible with an appendage. First 
pair of legs subchelate, others simple; first four pairs articulated to 
body at the anterior ends of their segments and directed forwards, 
last three articulated at posterior ends of their segments and directed 
backwards. Abdomen long, of six distinct segments, last joined to 
telson. Sixth pair of pleopoda biramous, styliform. Telson large, sub- 
conical. 
Phreatoicus typicus, sp. nov. Pl. IV. 
Eyes not visible. Upper antenna about half as long as the peduncle of 
the lower antenna, consisting of about eight joints, peduncle not distinguish- 
able from the flagellum, last three or four joints thieker than the preceding. 
Lower antenna about three-fourths as long as the body, peduncle of five 
joints, first two short, third longer but not so long as the fourth, fifth 
nearly as long as the third and fourth together. First pair of legs subchelate, 
propodos rather small, palm oblique, defined by densely haired knob; 
finger strong, hairy; next three pairs of legs subequal, rather stout; last 
three longer, setose, increasing regularly in length from before backwards. 
First segment of pereion only about half as long as the second, remainder 
subequal. Pleon two-thirds as long as pereion, first segment small, next 
three subequal, fifth large, about as long as the preceding three together, 
the second, third, fourth and fifth segments having the integument pro- 
duced inferiorly, and the inferior edge fringed with short stout sete. Sixth 
segment joined to telson and bearing a pair of biramous pleopoda ; peduncle 
longer than rami, outer ramus shorter than inner. Telson large, sub- 
conical, deeply concave below, inferior edge irregularly serrate and fringed 
with very short setz ; regularly rounded above, extremity projecting back- 
wards, with short sete on tip, and a stout one on each side of the 
base. i ; 
Colour—transparent. 
Length, about half an inch. 
Hab, Pump at Eyreton. 
Additional remarks on structure :— 
The upper antenna (pl. IV., fig. 2) is peculiar in having the last three 
or four joints considerably thickened, the thickening being chiefly due to 
the increased thickness of the integument. Small simple auditory cilia are 
found on the under side of the antenna (fig. 2 a). 
The lower antenna (fig. 3) has already been sufficiently described. 
