54 REV. A. M. NORMAN, M.A., 
The posterior antenne are long and slender; their peduncles 
are not very muscular, are corrugated on the basal half, and bear 
a few minute spines on the surface towards the distal extremity. 
The upper and four-jointed branch of these antenne has the 
first articulation very small, the second considerably longer, and 
furnished with a spine on the upper margin, but no seta; the 
third is unprovided with appendages; the fourth terminates in 
three two-jointed plumose sete and a spine, which does not equal 
one-third of the basal portion of the sete in length. The first 
joint of the lower branch bears an unusually long two-jointed 
seta of remarkable character, and which, indeed, forms one of 
the chief features in this interesting Entomostracan. The basal 
portion of this seta is provided with short cilia on the outer or 
upper margin, while the inner margin is smooth; the second 
portion of the seta (Pl. I. fig. 3) has a series of rather distant 
spines upon the outer margin; and between these spines a high 
power of the microscope shows a fringe of short, closely-set cilia. 
The second joint of the lower branch of the posterior antennz 
bears another seta of great length, which differs, however, in 
its armature from that of the first joint. The seta is plumose 
on both margins throughout its entire length; and between 
the longer hairs of the outer margin of the distal portion are 
short closely-set cilia (fig. 4), similar in character to those be- 
tween the spines of the seta which is attached to the first joint. 
The third joint ends in three two-jointed plumose cilia and a 
spine. 
The labrum has a large and conspicuous, much elevated, 
acutely papilliform process in front. The terminal portion of 
the abdomen is bordered with a closely-set array of spines, and 
has the sides, moreover, thickly studded with an admixture of 
slender spines and hairs. The abdominal setz are long, while 
the terminal claws (fig. 5) are rather short, a little flattened, 
and minutely pectinated along the edges. The ventral margin 
of the carapace is fringed throughout its entire length with 
plumose setee; and these sete attain an extraordinary length at 
the angle formed by the junction of the ventral and posterior 
margins. 
