38 MAINE AGRICULTURAL EXPERIMENT STATION. 1917. 



dd. Cephalic margin of fifth abdominal segment with 



four or five shallow furrows over each spiracle : 



mesothoracic spiracle always with a prominent 



elevation adjacent to its caudal margin. Diastictis. 



cc. Dorsal furrow present between the ninth and tenth 



abdominal segments, and a very prominent one on the 



dorsum of the fifth abdominal segment. Hydria. 



bb. Prothoracic femur never exposed. 



c. Dorsal furrow never present between the ninth and 

 tenth abdominal segments ; a prominent tubercle nev- 

 er present adjacent to each mesothoracic spiracle. 



Paleacrita. 



cc. Dorsal furrow always present between the ninth and 

 tenth abdominal segments ; a prominent tubercle ad- 

 jacent to each mesothoracic spiracle. Erainiis. 



Genus COSYMBIA Hiibner. 



Body much wider at the cephalic end and truncate, the 

 cephalo-lateral angles distinctly produced ; face-parts consider- 

 ably elevated, a transverse ridge extending across the front on 

 a line with the cephalic angle of the eye-pieces ; labrum quadrate 

 in outline ; labial palpi not visible ; maxillae reaching nearly to 

 the caudal margin of the wings, the proximo-lateral angles not 

 quite reaching the eye-pieces ; prothoracic legs almost three- 

 fourths the length of the wings, their femora exposed ; the legs 

 reaching cephalad between the sculptured eye-pieces and the 

 antennae $ mesothoracic legs reaching the caudal margin of the 

 wings, always longer than the maxillae ; tips of the metathoracic 

 legs showing caudad of the maxillae ; prothorax on the blunt 

 cephalic end of the body, scarcely visible in ventral view, its 

 mesal length one-third that of the mesothorax ; mesothoracic 

 spiracle with a large rounded tubercle adjacent to its caudal 

 margin which form the produced cephalo-lateral angles of the 

 body as seen in either dorsal or ventral view ; mesothorax with 

 a distinct lateral ridge which extends from the base of the spir- 

 acular tubercle caudad to near the anal angle of the wing ; mesal 

 length of metathorax one-fourth that of the mesothorax, the 

 caudal margin curved slightly at the meson ; abdominal seg- 

 ments smooth, never punctate; abdominal spiracles small, el- 



