482 NEW YORK STATE MUSEUM 



mottlings darker toward the middle line, and on the lateral ridges of the 

 thorax ; a darker band covering the top of the head, including the eyes, 

 but not the frontal horn, which is yellowish, sprinkled on its upper side 

 with brownish prickly granulations. 



Head compact, bulging behind the eyes, which cap the elevated 

 anterolateral angles ; antenna with the basal segment twice as long as 

 the second, about as long as the third; the succeeding segments gradu- 

 ally becoming a little shorter; hind angles of the head obtuse angled 

 superiorly; rear of head a little concave; prothorax with a flat, angular 

 fringed process each side, fitted snugly against the sides of the head; 

 tarsi with the second and third joints of about equal length, the first joint 

 about one third as long; femora and tibiae ringed obscurely with brown; 

 wing cases reaching almost to the apex of the sixth abdominal segment. 



Abdomen flat, with thin, flat lateral margins, and a median row of 

 large, cultriform, dorsal hooks on segments 3-9, these same segments 

 longer at the sides than on the median line ; long, straight, lateral spines 

 on segments 8 and 9, on 8 slightly divergent, on 9 parallel, as long as or 

 longer than the body of the segment ; loth segment annular, inserted into 

 an apical excavation of the ninth, one third as long as the length of the 

 ninth on its middorsal line; appendages about as long as 9 above, 

 subequal, or the laterals a very little shorter. Thorax broadly excavate 

 below for the reception of the labium, with a pair of supporting humps 

 beside it on the mesothorax and another one behind it on the metathorax. 



Labium large; mentum broadly triangular, strongly contracted at its 

 basal fourth, with a moderately prominent and declined median lobe, 

 and about seven raptorial setae each side, the two inner ones quite 

 small ; lateral lobe ample, concave, with five raptorial setae and a hook 

 that is stouter but little longer than the setae; distal margin with about six 

 or seven crenate oval teeth, each bearing several graduated spinules. 



MACROMIA 



Two species are regional, but only one of them has as yet been taken 

 within the state (M. illin oi en sis) ; the other (M. t aen iol a t a) is 

 found from Pennsylvania southward as far as Florida. Neither has as 

 yet been bred. Cabot ^ has described nymphs referred by supposition to 

 each. Till these are reared it is hardly worth while to repeat descrip- 

 tions in detail. It will suffice to give a general account of the characters 

 of nymphs of this genus, and to state in tabular form the chief differences 

 between the two species of nymphs believed to be the two species named. 



The nymphs of the genus are short and flat, with widely sprawling 

 legs. The shape of the prominent eyes, elevated on the laterosuperior 

 angles of the head, and of the frontal horn, ofler specific characters : the 

 head is widest across the eyes, and slowly narrowed behind them, to the 

 obtuse hind angles, each of which bears a tubercle on its upper aspect. 

 The wings reach well over the sixth abdominal segment. There are 

 strong cultriform, dorsal hooks on abdominal segments 2-9, and there is 



1 Immature state of the Odonata. 1890. pt 3. 



