396 The American Naturalist. - [May, 
long antennal joint and the body. The antenne seem to 
us to be four-jointed below the rami, and this view is strength- 
ened by the fact that in the young the three short basal joints 
are plainly marked. See Fig. 2. The third basal joint bears 
on the posterior a prominence armed with two slender spines. 
These spines show alsoin the young. See Fig. 2. The fourth, 
a long stout joint of the antenna, bears on the anterior distal 
end, a short spine 45». long. All the joints of the antenne 
are ornamented with encircling rows of minute blunt spines, 
one row of which is located on the distal end. Rami of the 
antenne three. The outer four-jointed, the basal joint short 
and unarmed, the second armed with a short spine and not 
bearing a long two-jointed one as shown in Herrick’s figures. The 
two-jointed setæ arming the other joints of the outer and inner 
rami are plumose the whole length and not naked below as shown 
by Herrick. 
Third ramus short, located at the base and between the 
others. Composed of three joints, not two as stated by Herrick. 
See Fig. 7. | 
The basal joint short and broad, the second joint fusiform, 
' the terminal slender and hyaline. See Fig. 7. 
The prominence in front of the anus armed with eleven 
spines, the anterior longest, all curving backward. Body back 
from the anus abruptly angled and not gradually sloping 98 
shown in Herrick’s figure. See Fig. 3. There are two long 
caudal spines at the posterior part of the body not shown 
by Herrick. See Fig. 3. At the posterior ventral angle of 
the shell are four, not three, short stiff sete, differing trom 
the slender plumose sete forward. The seta arise not from 
the margin, but a considerable distance above the edge 
the shell and extend below it. The body of our form is muc" 
broader and deeper in relation to the length than shown m 
Herrick’s figures. 
In the body above the abdomen in most females were five 
oblong bodies. While examining one specimen, these bodies 
began to show motion, and soon were expelled as living young. 
One of these young is shown in Fig.2. The eye was two0” 
and the body filled with spherules of a greenish brown colar. 
=- 
