THE SUBFAMILY LIBELLULIN^. 265 



111. "Wings and abdomen short, the latter with parallel sides . *23. Erythrodiplaco. S. America. 

 Wings and abdomen not remarkably short, the latter 



tapering *25. Crocothemis. Old World. 



112. Fore wings with 18-20 antenodal cross nervures 60. BJwdopygia. S. America. 



Fore wings with 7-14 antenodal cross nervures. (113.) 



113. Fore wings with triangle rather broad; 7 or 8 antenodal 



cross nervures placed rather widely apart ; very rarely 



9 or 10 *20. Sympetrum. Cosmopolitan. 



Fore wings with triangle not remarkably broad; 8-14 

 antenodal cross nervures (generally 9-11) placed 

 rather closely together *22. Trithemis. Cosmopolitan. 



PART III. 



Chakactees of Genera. 



Genus 1. Tholymis. 



Hagen, Stett. ent. Zeit. xxviii. p. 221 (1867) ; Brauer, Verh. zool.-bot. Ges. Wien, xviii. pp. 365, 

 712 (1868). 



Frontal tubercle truncated above ; eyes connected by a long suture ; face very hairy ; 

 abdomen moderately slender, as long as the hind wings, segments 2 and 3 a little 

 thicker than the remainder, and 2-4 carinated, dorsal and lateral carina? very slightly 

 marked, segment 8 not perfoliate in female : wings rather short and broad, tips rounded 

 off, pterostigma moderately long; fore wings with 10-12 antenodal and 7-11 postnodal 

 nervures, the last antenodal and first two or three postnodal nervures not continuous, 

 cells of the lower postnodal space generally simple (bisected at the extreme tip only in 

 T. pallida, Brauer), triangle on nearly the same plane as that of the hind wings, 

 moderately long and narrow, oblique, traversed by one nervure, and followed by three 

 rows of cells, no supratriangular nervures, nor more than one nervure in the lower basal 

 cell, subtriangular space consisting of three cells, sectors of the arculus stalked, nodal 

 sector waved, lower sector of the arculus broken towards the extremity, lower sector of 

 the triangle in this and the seven following genera often very irregular ; hind wings 

 broader than the fore wings, with 7-8 antenodal and 8-11 postnodal nervures, last 

 antenodal always continuous, the first two or three postnodals not so ; triangle free, 

 followed by two rows of cells, the sectors sometimes separated at the base (T. citrina, 

 Hag.) : anal appendages rather long. 



Type Libellula tillarga, Fabr. 



Genus 2. Pantala. 



Hagen, Neur. N. Amer. p. 141 (1860) ; Brauer, Verh. zool.-bot. Ges. Wien, xviii. pp. 364, 713 

 (1868). 



Frontal tubercle broad, with a slight depression in the middle ; eyes connected by 

 vol. xn. — part ix. No. 3. — August, 1889. 2 r 



