O D O N A T A 



GOMPHINA. 



1. Herpetogomphus species. 



Selys, Monogr. des Gomph., p. 69. 



Plate I., fig. 2, b, c. 



Locality : Brazil, Rio clos Macacos, Thayer Expedition. Nympha, 

 male, full grown. Mus. Comp. Zool. Length, 31 mm. ; breadth, 7 mm. 



Body ^schna-like, rather tlat, hairy. Head cordate, flat. Eyes 

 moderately prominent. Ocelli developed ; an oblique groove extend- 

 ing from lateral ocellus to front angle of eye ; part behind the eyes 

 short, notched at middle, with flat spot on each side ; hind angles 

 rounded with circular tubercle. Antenniv, two basal joints short, glob- 

 ular ; 3d long, dilated, straight, bent up a little at tip ; 4th joint very 

 short, rudimentary. Mask extending to fore legs ; breadth half the 

 length, narrower behind, sides bent up ; somewhat marginated; middle 

 third of fore-border produced in rounded lobe edged with bristles, and 

 having two small black teeth on each side of middle. Palpi small, not 

 meeting, finely denticulated ; end hooks sharp, bent down ; movable 

 hooks long, arcuated. Prothorax narrower than head, with short an- 

 terior lobe ; posterior part rounded, has two quadrangular impressions. 

 Wing-cases reaching middle of fourth segment. Legs short and strong, 

 formed for burrowing. Hind legs more distant at base. Fore and 

 middle legs alike ; femora and tibiae strong, somewhat bent ; tibiae 

 longest ; tarsi less than i as long as tibiae, 2-jointed, basal joint very 

 small; claws small, sharp. Hind legs reaching 9th segment, rather 

 flattened ; tarsi 3-jointed. Abdomen long, gradually narrowing to tip, 

 somewhat rounded above and flattened l)elow. Segments 2 to 9 have 

 dorsal hooks, thicker on 2d segment, nearly obliterated (accidentally ?) 

 on 6th, more marked on those following. Side-border sharp. Lateral 

 spines on segments 7, 8, 9 ; Segments of equal length, 10th segment a 

 little longer than 9th. Anal appendices long, sharp, pyramidal, 2 in- 

 ferior ones as long as 10th seg. ; superior a little shorter, basal half 

 thickened above ; lateral appendices -^ as long as inferior. 



