58 ENTOMOLOGICAL NEWS [Feb., ’11 
Anisopleura and Cora larvae with those of the Ephemerid 
larvae until much fuller data are at hand regarding the de- 
tailed structure, position, musculature and tracheation of each. 
The present study of Cora larvae supplies much fuller informa- 
tion than exists for either of the other two Odonate genera 
mentioned. The markedly ventral position of the gills in 
question in Cora is in itself some evidence against homolo- 
gizing these structures with those of the Ephemeridae and 
in favor of their own serial homology with thoracic legs. No 
traces of these gills are present on the exterior of the abdo- 
men of imagos of Cora preserved in alcohol immediately 
after capture. 
The caudal tracheal gills of Cora larvae are very different 
in shape from the similarly situated gills of all other Odonate 
larvae yet described, including those of Euphaea (cf. Folsom’s 
figure, J. c.) and Anisopleura, of which latter I possess a pho- 
tograph from Hagen’s specimen, taken and given to me by 
Prof. J. G. Needham. In both of these latter two genera the 
caudal gills taper posteriorly to an acute apex. 
As related in the opening pages of this paper, the attempt to 
rear these larvae to transformation was unsuccessful. That 
they are the larvae of Cora and, so far as the Juan Vinas 
specimens at least are concerned, the larvae of Cora chirripa 
Calvert (1907, p. 348) is rendered practically certain from a 
comparison of the wing-rudiments of larva No. 4 with those 
of an imago of this species taken at the same ditch April 30, 
1g10. The left hind wing-pad of larva No. 4 was slit open, 
the wing rudiment removed from within and examined in 
alcohol under the compound microscope. The inner and outer 
surfaces of the rudiment gave the views represented in PI. III, 
figs. 23 and 24 respectively. The veins shown in these figures 
are bands of reddish-brown pigment granules in the rudiment 
itself. The left hind wing of the imago mentioned was com- 
pared with camera drawings of the two surfaces of the wing- 
rudiment of the larva. At first the identification of the larval 
wing veins proceeded slowly until it occurred to me that per- 
