73 



Atlantic coast states, but seems less abundant in Illinois than 

 some other species. Walsh notes an imago taken June 16 eat- 

 ing one of the larger caddice-flies, Macronenia zehratum. Kelli- 

 cott ('96, p. Ill) describes the habits of the imago as similar to 

 those of fraternus, and says they copulate at rest in trees or 

 shrubs. The time of flight seems to be from the latter part of 

 May through July. Our Illinois imagos are all from the vicin- 

 ity of the Mississippi along the northwestern border of the 

 state. Williamson says they frequent the larger rivers and lakes, 

 the males being more often found near the water's edge, the 

 females in fields or along roadsides. 



The nymph has been described and figured by Cabot ('72, 

 p. 3, PI. II., Fig. 4) and again by Hagen ('85, p. 265). The fol- 

 lowing brief description is condensed from that of Dr. Hagen. 



The nymph measures 31 mm. in length. 



The mentum of the labium is one third longer than broad; 

 the front border of the median lobe is straight, fringed with loyuj 

 flat scales : the lateral lobes end in a long sharply incurved 

 point, inside which the toothed inner margin is concave. Ab- 

 domen slowly tapering posteriorly, in outline rather bluntly 

 pointed. Ninth abdominal segment three times as long as the 

 10th, and a little longer than the 8th. Lateral spihes on the 

 6th to the 9th segments, those of the 9th as long as the 10th 

 segment. Dorsal hooks on the 8th and 9th segments. Ap- 

 pendages nearly twice as long as the 10th segment. 



7. (romphus ventricosus Walsh. 



A widely distributed but rare species in collections. It was 

 originally described from Rock Island, 111., and has since been 

 listed from Michigan, Massachusetts, and Virginia. The nymph 

 is unknown. 



8. Goinphus fraternus Say. 



This species and the following [extent us) are closely related 

 but specifically distinct. The nymphs of //7//p/'///f.9, if any are 

 in our collections, have not been distinguished from those of 

 externus, which is a common species at Havana. Dr. Hagen's 



