Z83 LEPIDOPTERA OF NORTH AMERICA. 



Fam. I. CTENUCHIDAE. 



Gkoup I. 



Hind wings without costal vein. The subcostal vein bifid from 

 the origin of the discal, or posterior to it (Acoloithus), the lower 

 branch more or less angulated towards its base. Discal vein sim- 

 ple, angulated usually beneath the middle of the disk, receiving a 

 more or less thickened discal fold. Median vein 4-branched, with 

 the posterior sometimes remote from its penultimate. In the fore 

 wings the subcostal vein is not remote from the costa and its 

 branches are decumbent, except in Acoloithus. 



ACOLOITHUS Clemens. 



The following insect greatly resembles Americana in appear- 

 ance and almost exactly in ornamentation. It must, however, be 

 very distinct from it. The wings are extremely narrow. Hind 

 wings broader than the fore wings, less ovate than in Amei-icana, 

 and rounded at the interior basal angle ; length rather more than 

 that of the body. The disk of the fore wings is closed by a rather 

 faint, irregularly oblique vein, with one disco-central nervule, and 

 angulated at the medio-superior nervule, where it receives a rather 

 faint discal fold. The subcostal vein with three equidistant, mode- 

 rately erect marginal nervules frotn the disk, with the apical vein 

 simple. Median vein 4-branched, with the posterior nervule and 

 the marginal opposite at their origins. The fold is thickened and 

 the submedian vein simple. In the hind wings the subcostal vein 

 shows a tendency to separate into two veins from its point of bi- 

 furcation towards the base of the wing and resembling two veins 

 crossing each other ; exterior to the point of bifurcation and a 

 little l)ehind the middle of the lower branch arises a decided, curved 

 discal vein which receives, just above the medio-superior nervule, 

 a decided or thickened discal fold. The median vein is 4-branched, 

 with the two posterior branches equidistant from the second one. 



Head moderate, free," smooth ; with large ocelli. Face broad, 

 rounded. Eyes rather small, round and scarcely prominent. An- 



