EPHEMEBIN^E. 563 



Yellowish white: head sessile; vertex ferruginous: thorax 

 with two ferruginous vittae, confluent before and becoming obsolete 

 behind : setae with black rings, hardly longer than the body : legs 

 white ; fore-femora ferruginous at the tips ; lips of the fore-tibiae 

 and of the joints of the fore-tarsi brown : veins of the wings except 

 those of the margin, black; hind-wings not extending beyond the 

 fourth abdominal segment. Length more than J of an inch. 



Indiana. 



26. BAETIS OBESA. 



Brews; alee nigricantes, maculis una magna plurimisque parvis 

 hyalinis. 



Bae'tis obesa, Say, Journ. Acad. Nat. Sci. Phil. viii. 43, 4. 



Subimago. Very short and robust, blackish livid : borders of 

 the abdominal segments dull rufous, livid : setae very short, hairy, 

 with black rings : legs pale yellowish ; tips of the joints of the tarsi 

 black : wings dark brown or blackish, with numerous small, trans- 

 verse, hyaline spots or abbreviated lines, and a large, hyaline, very 

 oblique seuiifascia about the middle on the anal half: hind-wings 

 with numerous transverse abbreviated hyaline lines, which do not 

 extend to the apical margin. Length over T ^ths of an inch. 



Indiana. 



27. BAETIS LURIDIPENNIS. 



Pusca ; abdomine cingulato ; alls luridis fusco venosis. Long, 

 mar. 7 lin. ; fcem. 9j lin. 



Bae'tis luridipennis, Burnt. Handb. Ent. ii. 2, 801, 7. Pictet, Hist. 

 Nat. Neur. Eph. 192. 



North America. 



B. luridipennis P Male. Tawny: antenna brown, tawny at 

 the base : abdomen with brownish bands on the sutures of the seg- 

 ments, less than twice the length of the thorax : setae whitish, very 

 minutely pubescent, a little more than twice the length of the body : 



3 c 2 



