14 E. B. WiLUAMSON 



the metastigiiia, a spot at tlie upper end of tlie second lateral suture, and a spot 

 or stripe posteriorly on the latero-ventral carina ; legs pale colored ; venation 

 complex, two rows of cells between Ma and AL immediately following the loop 

 in M,; wings hyaline to tinged yellowish brown or with a brown or brownish 

 longitudinal stripe near the costal margin; sternum of abdominal segment i witli- 

 out a median apical tubercle. Auricles of male not greatly enlarged; the ventral 

 carina on abdominal segment 2, posterior to the point of convergence, straight or 

 convex, never concave, meeting the lateral carina in a more or less rounded 

 angle; spines of anterior lamina directed caudad and slightly ventrad. So far 

 as observed, flying for a short time in tlie evening just l)efore dark or rarely 

 in dark woods during the day nervosa group. 16. 



8 (7). Legs pale colored, yellowish or reddisii 9. 



8'. Legs black or black and yellow, bases of femora m )re <jr less i)ale 



tibiata group. 15. 



g (8). No distinct brown stripe on the first lateral suture; anal loop normally 

 separated by two or three rows of cells from the posterior wing margin 10. 



9'. A distinct brown stripe on the first lateral suture ; anal loop separated by a 

 single row of cells from the posterior wing margin caiidata Rroup. 14. 



10 (9). Smaller species, hind wing less than 45 in length. Auricles of male in 



lateral view not extending caudad to the level of the transverse carina at mid- 

 height. In the female the lateral and ventral carinae on abdominal segment 2 

 subparallel i ' • 



10'. Larger species, hind wing 45 or more in length. Auricles of the male very 

 large, expanded, in lateral view extending caudad far beyond the level of the 

 transverse carina at mid-height; spines of anterior lamina not directed more 

 ventrad than caudad. In the female the lateral and ventral carina on abdominal 

 segment 2 diverging anteriorly, and the abdominal appendages shorter than the 

 last two segments auricularis group. 13. 



11 (10). Spines of anterior lamina of male directed more ventrad than caudad. 



Female not as in 11' i-^. 



11'. Wings not brown spotted at base. Male with spines of the anterior lamina 

 dire,cted more caudad than ventrad, and two cells between anal loop and anal 

 triangle in first row posterior to A. Female with wing bases hyaline and four 

 cells posterior to A and proximal to the anal loop adela. 



12 (11). Base of wings hyaline. Abdomen of male not constricted at ."? and in 



the female the distance between the lateral and ventral carina on, the same seg- 

 ment less narrowed than in coiivergens. In the male one cell between the anal 

 loop and the anal triangle in the first row posterior to A, and in the female 

 three cells in the first row posterior to A and proximal to the anal loop ; the 

 smallest species laticeps. 



12'. Base of wings tinged brown nearly to or slightly beyond the first antenodal. 

 Abdomen of male constricted at 3. and in the female the distance between the 

 lateral and ventral carinae on the same segment narrowed at the level of the 

 transverse carina to about one-half the width posterior to this point. In the male 

 two cells between the anal loop and the anal triangle in the first row posterior 

 to A, and in the female four cells in the first row posterior to A and proximal 

 to anal loop convcrgens. 



13 (10'). Auricles of male large, not brilliantly colored ventrally, the black edge 



not produced anteriorly on the ventrum to the level of the hamular process ; 

 no teeth on the ventral carina of segment 2. Female with abdomen not con- 

 stricted at 3; lateral carina on 2 uniformly low throughout its length, auricularis. 



