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 (PI. Ill, fig. 

 28 /*) 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. Ixv) noted the existence of "une plantula 

 entre les onglets" of Euphaea larvae and remarked (p. Ixvii) 

 "La presence d'une plantula entre les onglets est aussi un 

 caractere 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 Anisoplcura in the very brief 

 description of Hagen (1880). One of these larvae was figured 

 by Folsom in Packard (1898, 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. Diirken (1907, 1909) and 

 Borner (19090) 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, 



