218 THE AMERICAN NATURALIST. [Vor. XXXIV. 
peduncle of the first pair of antenna. Flagellum of first pair of 
antennze composed of four to six joints. Abdomen relaxed. 
. Eyes present. Anterior pairs of legs with propodus more or less 
expanded, dactylus forming a very large and evenly curved 
hook. Mandibles with the cutting edge expanded inside to 
a linguiform lamella ; palp well developed, with basal joint 
much elongated. Abdomen not much narrower than thorax. 
Rocinela Leach 
8. Eyes wanting. Anterior pairs of legs with propodus not expanded, 
dactylus abruptly curved in the middle, and terminating in a 
very sharp point. Mandibles with the cutting edge simple, 
acuminate; palp of moderate length. Abdomen narrowing 
abruptly to a much smaller width than the thorax ; terminal 
segment very large. . . . « + + + + Syscenus Harger 
Genus Æga Leach. 
a. Peduncle of the first pair of antennz plane or concave, joints fitting 
into each other. Frontal lamina plane or concave. 
b. Terminal segment of body pointed at extremity. Eyes distant. 
: 4: ga psora (Linn), N, 30-218 fms. 
2’. Terminal segment of body not pointed at extremity. 
c. Terminal segment posteriorly bisinuate. Surface of segment 
smooth, without carina. 
Æga ecarinata Richardson, G, 88 fms. 
c. Terminal segment emarginate or truncate. 
d. Terminal segment emarginate. Eyes distant. 
Aga webbii Güerin, S, 333 fms. 
d'. Terminal segment truncate. 
e. Eyes contiguous. Propodus of the posterior pre- 
hensile legs with a cultriform lamina. 
Æga crenulata Lütken, N 
e. Eyes not contiguous. Propodus of posterior pre- 
hensile legs without cultriform lamina. 
Æga lecontii (Dana), D 
a’. Peduncle of the first pair of antennæ well rounded and with joints com- 
pressed. Frontal lamina convex or compressly elevated. 
b. Eyes contiguous. Terminal segment incised. 
ga incisa Schiœdte and Meinert, S, 263-440 fms. 
V. Eyes not contiguous. 
c. Terminal segment linguate, incised posteriorly. 
Æga arctica Lütken, JV. 
c. Terminal segment triangular, entire. 
d. Terminal segment, with apex rounded. 
ga microphthalma Dana, D 
d'. Terminal segment, with apex produced. 
Ega ventrosa Sars, N, 120 fms. 
