no. 2089. NOTES ON NEOTROPICAL DRAGONFLIES— WILLIAMSON. 619 



KEY TO THE GENERA AND SPECIES. 



a 1 . Wings narrow, width about one-seventh the length or less; first antenodal costal 

 space longer than the third, and about twice or more the second; R s arising at 

 the subnodus, M 3 proximal; M 2 arising at or just proximal to the fifth postnodal 

 in the front wings, at or just proximal to the fourth in the hind wings; M 3 ending 



distal to the stigma Protoneura. 1 



b l . Cu 2 ending against or at the termination of the cross vein descending from the 



subnodus. 2 



c 1 . Wings extremely narrow, the width about one-eighth the length; base to 



nodus over one-third the wing length and equaling the distance from the 



nodus to beyond the sixth postnodal; first antenodal costal space nearly 



equaling the other two calverti. 



c 2 . Wing width about one-seventh the length; base to nodus about one-third the 

 wing length and equaling the distance from the nodus to beyond the fifth 

 postnodal; first antenodal costal space only slightly longer than the 



third corculum. 



b 2 . CUi produced beyond the cross vein descending from the subnodus; otherwise 

 like corculum above. 3 The Central American species may be separated as 

 follows: 

 c 1 . Inferior appendages of the male as seen in profile with an acute superior 

 tooth, or the inferiors longer than the superiors; dorsum of thorax of female 

 predominantly black, or mesostigmal spine wanting. 

 d 1 . Male and female thoracic dorsum predominantly black; female with meso- 

 stigmal spine present. 

 e 1 . Abdominal segments 3-7 of male with small dorsal basal blue spots; female 



not separable from the next species cupida. 



e 2 . Dorsum of abdominal segments 3-7 of male basally three-fourths or more 



red; female not separable from the preceding species amatoria. 



d 2 . Male and female thoracic dorsum predominantly orange; dorsum of 

 abdominal segment 3 of male with basal half or more yellow, 4-7 with very 

 narrow basal rings (or wanting on 5-7); female without mesostigmal 



spine aurantiaca. 



c 2 . Inferior appendages of the male without an acute superior tooth, abdominal 

 segments 3-7 with deep yellow narrow basal rings; female without meso- 

 stigmal spine cara. 



i Protoneura peramans Calvert from Guatemala is known to me only from descriptions and I am not 

 certain of its generic position. Specifically it may be recognized at once by. the following characters: 

 Abdomen, male 42-43 mm., female 36-37 mm.; hind wing, male 23-24 mm., female 25.5-27 mm. ; R a arising 

 at the subnodus, M 3 proximal; Cui produced beyond the cross vein descending from the subnodus; M2 

 arising nearest the sixth or seventh postnodal in the front wings, nearest the fifth in the hind wings. 



2 P. paucinervis Selys and P. exigua Selys probably belong here, but are known to me only from descrip- 

 tions which do not enable me to determine their relationships to calverti and corculum. Some specific 

 characters of the 4 species are discussed under calverti. 



3 Four South American species may belong under & 2 under a>, or more probably they belong in Epipleo- 

 neura under &i under a 2 . The 4 species may be briefly discussed: 



ephippigera Selys.— Male. Thorax above and laterally, excepting the metepimeron, shining black; 

 abdomen 35-37 mm., hind wing 20-22 mm.; female not known; South America. 



humeralis Selys.— Female only known; considered by De Selys as possibly the female of ephippigera; 

 mesepisternum and mesepimeron black with a yellow humeral line; posterior border of prothorax with a 

 V-shaped excavation; abdomen 28 mm., hind wing 20 mm.; South America. 



tenuis Selys. — Not well described and known only from Do Selys's notos on 3 specimens from the Amazon. 

 The original description (1860) and the later note (1886) have little in common; abdomen 26 mm., hind 

 wing 16 mm. 



capilliformis Selys.— Male. Mesepisternum and mesepimeron black, with a fine, obscure, incomplete 

 line on the middorsal carina; abdomen 27 mm., hind wing 16 mm.; female not described, though, lo He 

 Selys's original Brazilian record, Calvert adds 3 males, 1 female (Odonataof the Neotropical Region, Ann. 

 Carnegie Mug., p. 212). 



