258 



CONNECTICUT GEOL. AND NAT. HIST. SURVEY 



[Bull. 



reach at all times. It keeps near the surface of the water and is 

 seldom seen except in sunny weather. The nymph crawls upon 

 the bottom but is said to be a good climber (Needham, 1901). 



Perithemis domitia (Drury) 



Illustrations of Natural History — Exotic Insects, 2: pi. xlv, f. 4: 1773. 



Nymph (PI. iv, Fig. 3). — Head: labium (Fig. 65) with 7-9 

 mental setae, and 5 setae on the labial palpi ; teeth of palpi fairly 

 deep, each with one or two long spines and a shorter one along- 

 side; dorsal surface of head behind the middle of the compound 

 eyes uniformly setose, not ridged. 



Thorax : hind femora extending to the seventh abdominal seg- 

 ment ; wing-cases to the sixth. 



Fig. 65. Labium of the nymph of Perithemis domitia, greatly enlarged. 



Abdomen : heavy dorsal hooks on segments 3-9 inclusive, and 

 lateral spines on segments 8 and 9 ; terminal appendages short, the 

 laterals about half the length of the superior, the latter nearly as 

 long as the inferiors. 



Measurements; exuviae: total length, 14-15 mm.; length of 

 abdomen, 8.5 mm. ; greatest width of abdomen, 5 mm. ; length of 

 hind femora, 5.5 mm. 



The length of the mentum is a distinguishing feature of this 

 nymph, it being much shorter and the palpi proportionally longer 

 than other genera and species. By referring to Fig. 65 it will be 

 seen that the distance, B, from base of labial palpus to the base 

 of the movable hook, is longer than the distance. A, to the base 



