152 BOARD OF AGRICULTURE. 



dorsum or upper part of the thorax black in the male, red in 

 the female; abdomen red to tlie seventh segment or joint, whose 

 sides are black, with the remaining segments of the same color ; 

 feet pale yellow, wings hyaline, expanding about an inch and a 

 quarter ; pterostigma rliomboidal, fuscous, length, one inch or 

 less. This is one of our smallest species. The tribe Aesc/mina, 

 derived from a Greek word meaning hideous, comprises the 

 largest and most formidable of our dragonflies or large-bodied 

 neuroptera whose eyes are less distant, some appearing as if 

 soldered together above, for a short space, wings unequal, the 

 hinder pair being generally broadest near the base, and having 

 an opaque spot, called membrctnule, on the inner basal angle, 

 behind the joints of the wings which varies in color and size in 

 different species. The abdomen in this family is cylindrical 

 and sometimes longitudinally carinated, (having a slight ridge 

 like the keel of a boat.) Of the genus Anax of Leach, meaning 

 a prince or king, Ave have only one species. Anax Junius, 

 Drury. The Junius dragonfly is of a fine pea-green color, 

 spotted with blue and fuscous, head yellow with a black spot 

 and circular blue band above ; thorax green ; feet black, femora 

 somewhat reddish ; abdomen long, nearly cylindrical, mucli 

 inflated at base. Tlie first segment or joint and base of the 

 second, green, the remainder blue with a longitudinal fuscous 

 stripe, sometimes broken, wings hyaline, slightly clouded witii 

 yellowish in some specimens, pterostigma yellow, membranule 

 black for two-tliirds of its length, the rest, toward the head, 

 white. Length, three inches, wings expand over four inches. 



The typical genus Aesdina of Fabricius, comprises many of 

 our New England species, the largest of which is Aeschna 

 /irros of Fabricius, or the hero dragonfly. It is not uncommon 

 throughout North America, and may be readily distinguished 

 by its great size, being over three inches and a half in length, 

 from the front of the head to the tip of the anal apj)cndages, 

 while the wings expand about five inches. It is often seen 

 alone at some distance from the water, and is exceedingly 

 active in its motions, soaring and circling like a hawk, whence 

 this and some other species have in various parts of the coun- 

 try received the name of " mosquito hawks." Its size and 

 swiftness enable it to cai)ture and destroy the largest butterflies 

 and moths, and it is to l)c reckoned one of the most beneficial 



