22 L J une, 



the imagines, correspond with differences in the nymphs ; and, con- 

 sequently, I am disposed to accept these differentia as bases for the 

 distinction of genera, although they are only in a few instances 

 accompanied by differences in the neuration of the wings, or in the 

 number of the caudal seta?. To make a complete survey of this group 

 of genera, Ametropus may as well be referred to. 



Ametropus, Albarda. 

 Intermediate tibia shorter than the tarsus, the proximal joint of 

 the latter about half as long as the former. Fore tarsus in $ about 

 four and three-fifths, in $ about twice and two-thirds, as long as the 

 tibia ; the proximal joint in $ once and a half, in $ three-fifths, as 

 long as the tibia, Three long caudal setse. Type, A. fragilis, Alb. 

 Distrib., Holland. 



Atopopus, n. g. 

 Hind tibia about half as long as the tarsus, the proximal joint of 

 the latter rather longer than the former. Fore tarsus in $ nearly 

 one and two-fifths, its proximal joint almost half, as long as the tibia. 

 The proportions of the intermediate tarsus are more largely in excess 

 of the tibia. Relative lengths of tarsal joints : — fore leg, 24, 18, 14, 

 8'5, and 6 ; intermediate, 31, 11, 7, 4, and 5 ; hind-leg, 305, 9, 6, 3, 

 and 5. Two caudal seta?, in <$ about twice as long as the body. Type, 

 A. tarsalis, sp. n. Distrib., Borneo. 



Atopopus tarsalis, n. sp. 

 Imago (dried). Body above piceous-black, with the last segment or two of the 

 abdomen flavescent ; belly flavescent. Fore- leg piceous-black, the femur to the 

 middle piceous-brown ; hinder-legs with femora piceous-brown, tibiae flavescent, 

 and tarsi rather deep fumatose, with the joinings and apical joint darker. Wings 

 vitreous, with black neuration : fore-wing with the marginal area beyond the middle, 

 and in part nearer the base, the sub-marginal area almost to the base, and a short 

 narrow cloud upon the terminal margin by the anal angle, and the hind-wings like- 

 wise bordered round the apex and along the terminal margin, piceous-brown. Setae 

 piceous-black. Long, corp., J > 9 — 10 ; al., 11 ; set. 20 mm. 



Ilab. : Labium. 



TlIALEROSPIIYRUS, 71. g. 



Hind tibia of $ as long as the tarsus, whose proximal joint is 

 about a third as long. Fore-legs damaged in the specimens examined 

 by me. Relative lengths of the posterior tarsal joints : — intermediate 

 tarsus, 10, 7, 5, 3, and 4 ; hind tarsus, 10, 7*5, 6, 3, and 4. Two caudal 

 seta? incomplete. Type, Th. determinatus (in Baetis), Walk. Distrib., 

 Java ami the Philippines. 



