Williams' "The Aphididae of Nebraska" 13 



Although brief, this description notes as present in cnici 

 Schrank one of the salient characters present in cnici Williams, 

 namely the " stumpfe Spitze " on the dorsum of the penultimate 

 abdominal segment. The other characters given by Schrank 

 agree fairly well with those of cnici Williams and the two are 

 apparently identical. 



Characters not mentioned by Williams in his description are as 

 follows. In the original description no mention is made of the 

 presence of sensoria on antennal segment V, although, with one 

 exception, all of the winged individuals bear 2 to 4 small incon- 

 spicuous sensoria on this segment, not counting the large distal 

 one. Just above the style, on the dorsum of the penultimate 

 abdominal segment, is a long slender tubercle which might easily 

 be mistaken for the style. Williams refers to this tubercle as 

 follows, " apical segment drawn out into a blackish point, causing 

 the insect to appear as if supplied with two tails." Cornicles 

 reticulated at distal end; reaching to or a little beyond tip of 

 style. Style small and conical. The size of this species is that of 

 a typical Macrosiphnm. Camera Incida drawings of the head, 

 antenna, wing, cornicle, style and abdominal tubercle of the 

 winged viviparous female are shown in Plates II and III, figs. 

 31 to 37. 



48. A. gossypii Glover {A. ciicumeris Forbes). 



49. A. euphorbiae Kaltenbach. 



" Aphis euphorbiae Kalt. On Euphorbia corollata. Weeping 

 Water, Aug. 24, 1890." 



Two slides numbered 60 and 61 respectively, each bearing 

 winged and wingless viviparous females. 



50. A. frangulae Kaltenbach. 



" Aphis frangulae Kalt. No. 62. On Rhamnus lanceolatus, 

 Fremont, July 31, '90." 



All wingless on slide and most, if not all, are immature. The 

 aphis is small, the largest, and most likely mature individual, 

 measures 1.03 mm in length and 0.56 mm in width. Antennae 

 5-segmented. Cornicles rather short, measuring 0.095 ^nm in 



265 



