OP PHILADELPHIA. 413 



The wings are longer than the body, and the setse not longer 

 than the abdomen. 



EPHEMERA. 



E. HiLARis. — Minute, white; stethidium pale fulvous; abdo- 

 men with three lateral points. 



Inhabits Indiana. 



Body white; eyes black, double ; stethidium pale [44] ful- 

 vous ; pleura and pectus with a few abbreviated dusky lines ; 

 wings two, ample, costal margin slightly dusky; abdomen de- 

 pressed, with three brownish punctures on each side towards the 

 tip ; seta elongated. 



Length one-tenth of an inch. 



The smallest species I have seen. I caught several of them 

 about the candle, on the evening of September 4th. They vary 

 in having the brownish lines of the pleura and pectus obsolete, 

 or altogether wanting. 



FORMICALEO Geoff. 



1. F. OBSOLETUS. — Antennae white in the middle; abdomen 

 with white bands. 



Inhabits the United States. 



Head dull whitish, with a broad, dark, honey-yellow band be- 

 tween the eyes ; antennae fuscous, middle fourth whitish ; thorax 

 dull whitish ; wings hyaline : anterior pair with a few obsolete, 

 small, brownish spots or transverse abbreviated lines, two of 

 which on the posterior margin are oblique, and a somewhat 

 larger one on the costal margin near the tip ; posterior pair with 

 fewer spots, about three or four subcostal distant ones, and a 

 large one on the terminal fourth, and a less obvious apical one ; 

 abdomen blackish, with a whitish band on each segment; be- 

 neath with a broad blackish vitta each side over the feet from 

 the head to the abdomen ; feet fuscous, posterior pair with a 

 white annulus towards the tip, and at base and their tibia 

 whitish. [45] 



Length of body about one inch. 



This species is rather common. 



2. F. ? GRATA. — Wings at tip varied with black and pale car- 

 neous, 



1839.] 



