298 THE AMERICAN NATURALIST. [VoL. XXXIV. 
inner branch. First pair of antennz long, reaching to the end of the 
third joint of the second pair of antennz, and being nearly twice as 
long as those of C. stygia. 
Cecidotea nickajackensis Packard, Tennessee 
FAMILY XVI. JANIRIDA. 
a. Eyes dorsal Antennz of the first pair well developed, with multi- 
articulate flagellum, or with flagellum rudimentary. Antennz of the 
second pair long, with multi-articulate flagellum; peduncular joints 
not dilated. Mandibles with a three-jointed palp, and with cutting 
part separated from molar part by a deep incision. 
6. Head without any true rostrum. First pair of antennz extremely 
small, with flagellum rudimentary. Second pair of antenne of 
moderate length, without any distinctly squamiform appendage. 
First pair of legs not prehensile. Uropoda iud small, 
branches very short, nodiform  . FOE each 
&. Head with. prominent rostral ecce Cr in us. or xe a 
comparatively short rostral projection. First pair of antennz well 
developed ; flagellum multi-articulate. Second pair of antenna 
very much elongated, with a well-marked, scale-like appendage 
outside of third joint. First pair of legs prehensile. Uropoda 
largely developed, with branches slightly unequal. 
c. Head with lateral parts produced to very prominent acute lappets. 
Segments of thorax with lateral parts laciniate and produced. 
Caudal segment aE ood on each side, at the end, a triangular 
expansion . Ianthe Bovallius 
c. Head with bue jeu not PRIUS into lappets. Segments 
of thorax with lateral parts not produced, not laciniate. Caudal 
segment rounded, not expanded laterally . .  Janira Leach 
a’. Eyes lateral. Antenne of the first pair small, with flagellum obsolete. 
Antennz of the second pair short, with peduncular joints dilated, 
rudimentary flagellum composed of five articles, and equal in length 
to the width of the head. Mandibles with a three-jointed palp, and 
with cutting part composed of five teeth . . . Jzropsis Koehler 
Genus Jara Leach. 
a. Anterior margin of the head broadly excavated on each side over the 
* bases of the antenna. Extremity of terminal segment notched for 
the insertion of the uropoda, the median point being almost imper- 
ceptible . . . . Jara marina (Fabricius), JV, surface 
a’, Anterior margin of the nad nearly straight. Extremity of terminal 
segment with a double excavation, the median point reaching the 
extremity of the sides . . . . Jæra wakishiana Spence-Bate, A 
Genus Ianthe Bovallius. 
&. Head with prominent rostrum. 
