112 THOMAS SAY FOUNDATION 
food habits of the nymphs of this genus. Examination of stom- 
ach contents, however, has shown that they are herbivores, feed- 
ing largely on decaying vegetation. Frison (6) has studied the 
food habits of several species in this genus, and he found them 
to feed on ‘‘fragments of decaying leaves and diatoms.’’ 
Key to the Nymphs of ALLOCAPNIA 
1. Last segment of abdomen prolonged into a conspicuous coni- 
cal protuberance (males*) —. ..a..---- +4 «<0 See 2 
Last abdominal tergite broadly rounded, without a protuber- 
ance (females*). 
2. Wine pads absentior vestigial’ 20a... ee. viveipara (p. 114) 
Wing pads well developed (in some cases the wing pads are 
abbreviated.) if). sicc. t's + +1 4s sein teal openly oe eae B) 
3. Protuberance of tenth tergite no longer than the ninth ab- 
dominal tercitec 3 gn ee recta (p. 113) 
probably incisura (p. 115) 
Protuberance longer than ninth abdominal tergite ........ 
EE ee Rt, 8 ets Ges Sk, Wb pygmaea (p. 112) 
granulata (p. 114) 
mystica (p. 116) 
Allocapnia pygmaea Burmeister 
(Plate 10, figs. 153-158; Plate 30, fig. 218.) 
Length of body up to 8 mm.; antennae up to 3.2 mm.; cerci 
up to 3 mm. 
General color brown, becoming darker as the nymphs mature. 
Head slightly wider than pronotum; surface nearly smooth but 
in the maturer nymphs the occipital rugosities of the developing 
adult are quite noticeable; ocelli indistinct in some specimens; 
hind ocelli about twice as close to the eyes as to each other; an- 
tennae brown, smooth, with about forty-six to forty-eight seg- 
ments. 
Pronotum about as wide as long, somewhat widened posteriorly ; 
angles rather broadly rounded; front margin convex, hind mar- 
gin nearly straight ; surface somewhat rugose, pilose, with longer 
hairs on the outer margins. In mature nymphs the dark brown 
markings of the developing adult are very noticeable. Wing pads 
large; front ones far apart, directed backward and parallel to the 
body; hind ones much wider than the front pair, broadly tri- 
angular, and much closer together. Legs yellowish, flattened and 
* Mature male nymphs can usually be specifically identified by the struc- 
tures of the developing genitalia. In female nymphs the species can not be 
separated. 
