88 



[September, 



on the outer margin of the wings. The has the third joints of its 

 4-jointed forceps the longest, and the upper divisions of its double eyes 

 turbinate. Egg-valve of ? bipartite. 



Genus Baetis,* Leach. 



Syn. Baetis, B, Steph., Curtis. 

 Cloe, B, Burm. 

 Brachyphlehia, Westw. 

 Cloeon, Hagen, p., Etn. 



Type B. hioculatus, Lin. 



Distrib. — Europe ; Madeira, Egypt ; Hindostan ; Hudson's Bay. 



Section A, B. luteolus, Miiller, = 0. translucida, Pict. 



Eorceps as in Cloeon, egg- valve entire. Posterior wings acute, with 

 two simple veins. Branchial plates of the aquatic insect single. A 

 series of short, solitary, supplementary veinlets proceeds from the 

 outer margin of the anterior wing. 



Distrib. — England, Denmark, Switzerland, 1 sp. ; Germany, 1 sp. 



Section B, B. hioculafus, Lin. 



Syn. Brachyplilelia, "Westw. 



Species conforming to this, the typical section of the genus, differ 

 from the former group in the following particulars only. Anterior 

 wings with the short supplementary veinlets on the outer margin in 

 pairs. Posterior wings obtuse, with two or three longitudinal veins 

 (the second of which is either simple, bifid, or bipartite, according to 

 the species), and with more or fewer short supplementary veinlets at 

 the apex. The fourth joint of the forceps seems never to be pyriform 

 as it is in Cloeon, and in the preceding section of Baetis. 



Section (?) C, B. tristis, Hagen, = Cloe tristis, Hagen. 

 Distrib. — Ceylon. 



I have only seen a $ sub-imago of this species, which may typify 

 a separate genus. 



Mr. "Walsh and Dr. Hagen have described several N. American 

 species of Cloe\ but I have not seen any representatives of the sections 

 in which they have arranged them. 



* Probably a misreading of Beetis, the Latin name of a Spanish river (the Guadalquivir), which Ifl 

 used in Bonie atl««es. 



