BOPYRUS. 215 
continuous than in the male. The head also is immersed 
in the anterior segment of the body, its front margin 
forming a continuous curve with that of the body. The 
antennz are even smaller and more rudimental than 
those cf the male, the outer pair being apparently 
only three jointed, and the inner pair only two 
jointed, 
The mouth is comparatively rudimental in its structure, 
and is nearly concealed by a pair of oval operculiform 
foot-jaws, of which the anterior extremity is furnished 
on its inner edge with a small flattened and biarticulate 
appendage; beneath these foot-jaws and near their base 
are several minute lobes; the lower lip, on the contrary, 
is well developed, and forms with the labrum and man- 
dibles a sort of conical sucker, the mandibles being 
minute, pointed, and scarcely movable. 
The pereion is broad and flat, and the seven segments 
of which it is composed are closely soldered together, 
the lateral portions forming a rather strong border, 
beneath which are affixed the seven pairs of short, 
strong, prehensible feet, resembling those of the male 
in form. They are very small, so as not to extend 
beyond the sides of the body, and each is furnished 
at the base with a large plate-like appendage or valve, 
generally folded inwards, so as to form an incubatory 
pouch, which does not, however, entirely cover the central 
part of the underside of the body, leaving a wide open 
space, which allows the eggs and young to be seen; the 
anterior of these plates differs in form from the rest, and 
seems rather to be transformed into an appendage of the 
mouth, having its lower extremity obtuse, free and 
curved (fig. t)..- 
The pleon in this sex is broad at the base, but 
narrower than the pereion, and gradually decreases in 
