Vol. xxii] ENTOMOLOGICAL NEWS 57 
judged from Hagen’s description (1880, p. xlv). If Miss But- 
ler’s theory (1904, pp. 114, 119) of the homologies of the 
labium be correct, then the small, pointed teeth (Pl. III, fig. 
28 t*) near the middle of the distal margin, would represent 
the apices of the original laciniae. The interpretation of Bor- 
ner (1909, p. 113) is different and is essentially that of Ger- 
stacker, Heymons and others. 
Hagen (1880, p. lxv) noted the existence of “une plantula 
entre les onglets” of Euphaea larvae and remarked (p. Ixvii) 
“La présence d’une flantula entre les onglets est aussi un 
caractére unique chez les Odonates.” The empodium-like 
structure mentioned above for Cora and shown in PI. II, fig. 
12, appears to be an homologous part. 
The existence of tracheal gills on abdominal segments 2-7 
is the most interesting feature of Cora larvae. The only 
Odonata previously known to possess such structures are the 
larvae referred to Euphaea and Anisopleura in the very brief 
description of Hagen (1880). One of these larvae was figured 
by Folsom in Packard (1808, p. 469). Hagen stated that 
there were gills on abdominal segments 1-8, Folsom found 
them on 2-8 only. There are, therefore, one pair less in Cora 
larvae. Hagen compared these gills of Euphaea and Anis- 
opleura to those of Sialis, but makes no mention of Ephemerid 
larvae in this connection. Heymons (1896 a, pp. 88-90) com- 
pared the abdominal gills of Ephemerid and Sialis larvae, re- 
garded them in both cases as derived from abdominal ap- 
pendages and noted the agreement in the pointed form of the 
gills of the early larval stages of both groups. The gills of 
the second to seventh abdominal segments of Cora larva fur- 
nish an addition to this parallel. That the lateral gills of 
Ephemerid larvae are homologous with the thoracic legs is 
not universally accepted, however. Durken (1907, 1909) and 
Borner (1909 a) are the latest representatives of the two views 
which look upon the Ephemerid lateral gills as dorsal and not 
homologous with legs and as ventral and homologous, respec- 
tively. We may not compare the lateral gills of Euphaea, 
