354 
CLASS CRUSTACEA. 
dosed, if a sufficient quantity of rain should fall. M. Desma- 
rest has often observed branchiopoda in the small standing 
pools of rain water on the summits of the gres of Fontainbleau. 
The females of the chirocephali lay several distinct sets of 
eggs, after a single coupling, each at several times. These 
operations last some hours together, and sometimes as long as 
an entire day. Each laying produces from one hundred to 
four hundred eggs : they are sent out with much quickness, by 
casts of ten or twelve, and with sufficient force to sink a little 
in the mud. 
Benedict Prevost has observed that his Chirocephale dia- 
phane was subject to some maladies, the description of which 
he gives. This species, as we have said, appears to differ but 
little from our Branchipc dcs marais . The two horns situ- 
ated below the upper antennae are composed, in both sexes, 
of two articulations, the last of which is large, and arched 
in the male, very short and conical in the other sex. In the 
j BrancJiipus slagnalis the horns present but one articulation, 
and those of the male resemble, in their form, direction, and 
teeth, the mandibles of the males of Lucanus cervus . 
The following have no tail. Their body is terminated 
almost immediately ^t the end of the thorax and of the last 
feet. Such are, 
Eulimene, Latr. 
Their body is almost linear, and presents four short antennae, 
almost filiform, two of which are smaller, and almost similar 
to palpi, placed at the anterior extremity of the head ; a 
transverse head, with two eyes supported on peduncles tole- 
rably large and cylindrical ; eleven pair of branchial feet, of 
which the first three articulations and the last are smaller, 
going into a point ; and immediately after them a terminal 
piece, almost semi-globular, replacing the tail, and from which 
issues an elongated filament, which is perhaps an oviduct. I 
