440 NEW YORK STATE MUSEUM 



The superiors are well enough (and in these the chief distinctions between 

 this species and O. c a r o 1 i n u s Hagen lie), but the inferior is incorrect. 

 It is shrunken in the type from which the figure was drawn ; it should be 

 shown almost exactly as in O. carolinus, which is correctly repre- 

 sented in fig. 8 and 17 of the same plate. Mature specimens show also 

 a deep green color on the thorax, and often, the humeral and antehumeral 

 stripes of blackish brown entirely separated at their upper ends. 



The cast skin, pinned with the type, is not in fit condition for descrip- 

 tion, and the nymph is therefore practically unknown. 



HAGENIUS 



There is a single North American species. 



Hagenius brevistylus Selys 



1854 Hagenius brevistylus Selys, Acad. Belg. (2) Bui. 21 : 82 

 1861 Hagenius brevistylus Hagen, Synopsis Near. 1^. Am. p. 114 

 1890 Hagenius brevistylus Kirby, Cat. Neur. Odon. p. 75 (bibliography) 

 1890 Hagenius brevistylus Beutenmiiller, Dragon flies vs mosquitos. 

 p. 163 (listed from vicinity of New York) 



1892 Hagenius brevistylus Banks, Am. ent. soc. Trans. 19; 352 (listed) 



1893 Hagenius brevistylus Calvert, Am. ent. soc. Trans. 20 ; 241 (de- 



scription) 



1894 Hagenius brevistylus Banks, Can. ent. 26 : 77 (listed from Ithaca) 



1895 Hajifenius brevistylus Calvert, N. Y. ent. soc. Jour. 3 ; 44 (review 



of lists) 



1899 Hagenius brevistylus Kellicott, Odon. Ohio, p. 52-53 (good de- 



scription) 



1900 Hagenius brevistylus Williamson, Dragon flies Ind. p. 282-83 



(good description) 



Nymph 



1872 Hagenius brevistylus Cabot, Immature state Odon. pt 2, p. 9, pi. 3, 



fig. 4 

 1885 Hagenius brevistylus Hagen, Am. ent. soc. Trans. 72:279-80 



(very full description) 

 1897 Hagenius brevistylus Needham, Can. ent. 29 : 168 (characters 



stated in table for gomphine nymphs) 



This big species frequents clear streams, and is common throughout New 

 York state. It is very striking as an adult on account of its great size and 

 black color, and its nymph (pi. 18, fig. 7) is a most grotesque creature. 



At Saranac Inn the species was common along Little Clear creek. 

 The nymphs were found in the midst of the trash on the bed of the 

 stream, and, during the season of transformation, exuviae dotted the 

 banks rather conspicuously. Few imagos were seen at large. These fly 

 swiftly from one resting place to another about the stream. They are 



