226 PHILIP p. CALVERT. 



Characters of the subfamily... 16. Corilulegaster. 



Sithfamily Aeschninx. — Antennae 6t7 jointed ; tarsi 3-jointed ; labium flat, not 

 covering labrum or frons when closed. 

 Antennae 6-jointed. 

 Head broader than long; a lateral spine on 4-9, middle and inferior appen- 

 dages of equal length*- 17. Epijescliiia. 



Antennae 7-jointed. Head broader than long. 

 Hind dorsal margin of 9 concave. 



A lateral spine on 4-9, middle appendage sharply pointed. 



18. Foiisc<»lonibia.t 

 A lateral spine on 5-9, middle appendage bifid at tip. 



19. Goniplisesclina.t 

 Hind dorsal margin of 9 straight. 



Eyes more prominent at the fore corner; labium at rest extending back- 

 wards to the second legs; a lateral spine on 4, 5 or 6-9. % projec- 

 tion conical. 9 valves reaching apex of 9 20. Aeschna. 



Eyes more prominent In the middle; labium at rest extending back- 

 wards beyond second legs; a lateral spine on 7-9; middle appendage 

 notched at tip, laterals half as long. % projection cut at tip. 9 



valves shorter than 9 21. Auax. 



Family Lihellulidx. — Antennae 7-jointed; tarsi 3-jointed; labium spoon-shaped, 

 covering labrum and frons when closed. Some Libelluline nymphs 

 closely resemble those of the Cordulegasterinae (q. v.), but may he 

 distinguished by the teeth on the opposed margin of the lateral 

 labial lobes being so short as to form an almost straight line of union 

 when closed. Characters for separating Corduliue from Libelluline 

 nymphs are as yet unknown, as the latter subfamily has not been 

 monographed. J 

 Subfaniily Cordulinie : 



An erect pyramidal horn on the front of the head. 



No dorsal hook on 10 ; lateral spines on 9 reaching as far as level of tips 

 of appendages 22. Didymops. 



At least a small dorsal hook on 10 ; lateral spines on 9 mucli shorter than 

 in Didymops 23. Iflacroinia. 



* A clerical error in Part I has caused some confusion in regard to the appen- 

 dages of Anisopterous nymphs. For "lateral" should be read "inferior" on 

 page 196, line 25, p. 198, line 5 from bottom, and p. 199, line 3 from top. The 

 denial of the homology of the inferior appendages of the males of the Zygoptera 

 and Anisoptera (p. 199) refers, of course, to images only. Of the five appendages 

 which terminate the abdomen of older Anisopterous nymphs, two are ventral — 

 the inferiors, one is mid-dorsal (the middle) and on either side of it is a lateral. 

 corresponding to a superior appendage of the imago. 



t The identification of these is as yet doubtful (Cabot). 



X As this is going through the press Dr. Karsch has published a paper on " Die 

 Insecten der Berlandschaft Adeli" (West Africa) (Eerl. Ent. Zeit. xxxviii, pp. 

 1-226, July, 1893) in which he gives characters for the separation of Corduliiie 

 from Libelluline nymphs (p. 42). These characters will not serve for American 

 species, and his characters for those of the " Calopterygidae" are only those of 

 the legions Calopteryx and Libellago (?). 



