AMPELISCA GAIMARDII, 
129 
and below, two or three very minute hairs ; the second 
articulus likewise carries a single auditory cilium. The 
inferior antennae are as long again as the superior, and 
reach to about two-thirds of the length of the animal. 
The third and fourth joints of the peduncle are furnished 
on the upper margin with fasciculi of hairs, the former 
through the entire length, the latter for a portion only ; 
the last joint of the peduncle is longer and more slen- 
der than the preceding one : the flagellum, of which 
the first articulus is longer than either of the others, is 
very long and very slender, and is furnished with a few 
very minute cilia. The mandibles have the incisive 
margin armed with four or five strong teeth ; within is 
a second plate, articulated with the mandible, and equally 
strongly armed ; deeper within exists a broad strongly 
toothed molar process, between which and the moveable 
plate already referred to stands a row of stiff forked 
spines, each of which is denticulated along the margins 
throughout its length : the appendage of the mandibles 
has the first joint very short, not being longer than 
broad ; the second is very broad, and forms a long 
ellipse, having the upper margin furnished with four fas- 
ciculi of hairs ; the third joint is scarcely as long as the 
second, very much more slender, slightly curved, and 
of equal breadth throughout ; the underside is fur- 
nished with a few hairs, commencing near the middle, 
and increasing in length towards the apex. The foot- 
jaws have the finger long and slender ; the sixth joint, or 
hand, is short ; the wrist is longer than the hand and 
finger together, but the joint anterior to the wrist is 
very short, and carries a large squamiform plate, arcuate 
upon the outer, and straight upon the inner side, armed 
with six slightly-curved simple teeth, the most anterior 
K 
