522 NEW YORK STATE MUSEUM 



hi) Lateral spiues of the ninth segment straight on the inner, but inciirvate 

 on their outer margins 

 c Lateral spiues of the eighth segment thin, flat and sharp, attaining the 

 level of the apical margin of the ninth segment on the middorsal line 



vieinum 

 cc Lateral spines of the eighth segment stouter, their tips hardly surpassing 



the middle of the dorsum of the ninth segment semicintum 



oa Dorsal hooks of abdominal segments 6-8 shorter than the segments bearing 

 them, andlesspointed. assimilat um, r ubicundul um, obtrusum 



Sympetrum costiferum Hagen 



Figure 30 



1861 Diplax costifera Hagen, Synopsis Neur. N. Am. p. 175 

 1895 Diplax costifera Calvert, N. Y. ent. soc. Jour. 3:48 (listed from 

 Amherst) 



This species came up quite unexpectedly in one of my breeding cages 

 at Saranac Inn. I had collected a number of nymphs from the shore of 

 Little Clear pond near the outlet, and put them in this cage, supposing 

 them to be of one species; they yielded at transformation images of 

 S. vieinum, but one nymph yielded a fine male specimen of this 

 species. It is the one from which the characters stated herewith are 

 drawn. No imagos were seen at large. This one appeared on August 8. 

 The cast skin was left in a somewhat collapsed condition, so that it is 

 hard to measure accurately; but the measurements are, as nearly as 



I can make out, as follows: total length 14.5 mm; abdomen, 9 mm; 

 hind femur 5 mm; width of head 5 mm, of abdomen, 6 mm. 



The eyes are a trifle less prominent than in S. vieinum; there are 



II lateral setae, and about 13 mental setae, of which the fifth, counting 

 from the side, is longest, the movable hook is somewhat shorter and 

 thicker than in S. vieinum, and the teeth are more nearly obsolete; 

 the lateral spines of the eighth abdominal segment are about half as long 

 as is that segment; those of the ninth segment are much longer, slender, 

 straight on both margins, and their tips scarcely attain the level of the 

 tips of the appendages. The superior appendage is scarcely shorter than 

 the inferiors, but these laterally are less than one half as long. 



Sympetrum vieinum Hagen 



Figure 30 



1861 Diplax vicina Hagen, Synopsis Neur. N. Am. p. 175 

 1893 Diplax vicina Calvert, Am. ent. soc. Trans. 20:264 (description and 

 figure) 



