20 rilF. 1MMAII RE STATE OF THE ODONATA. 



lousj lateral spines on segments S and 9 short, triangular, sharp, on !) 

 slightly exceeding the liuh segment; dorsal hooks on segments 2 to 10, 

 small, erected on 2 to 5; long compressed, pointing backward on 6 to 9; 

 smaller but reaching beyond tip on 10; anal appendages tunning a pyra- 

 mid a little longer than broad; hairy, sharp, dorsal median as long as 

 inferiors; laterals a little shorter; ventral lateral spaces as broad as the 

 median one; ventral apical vi\<j:v of segment, 9 not fringed with hairs; the 

 female genitals very slightly marked by two small spines on the apical edge 

 of segment 9. Legs as in M. transversa, very long, thin, only a little flat- 

 tened; between the base of the hind legs an oblong pad; the four pos- 

 terior tibiae with a fringe of hairs. 



M. tseniolata is reported as found from Illinois and Pennsylvania as far as 

 Georgia, and will probably be found also in Florida. The large size of the 

 nympha makes the supposition very probable, as M. tseniolata is the largest 

 known species. 



7. MACROMIA SPEC 



Plate III. Fig. 1. 



Two probably full-grown nymphae in alcohol, from Cadereita, south of 

 Monterey, New Leon, Mex., by Mr. Couch, 1853. 



Length, 2o to 27 mm. ; breadth, 10 to 11 mm. 



Similar to M. annulata var. flavipennis. Body shorter, less elongated; 

 head very broad, eves small, projecting backward ; hind part of head 

 slightly depressed in middle, with some longitudinal wrinkles, which are 

 prolonged behind in two incurved branches ; sides of head behind the eyes 

 less prominent, convex ; occiput narrower, slightly notched, on the hind 

 angles a conical tubercle ; vertex small ; pyramidal horn broad, sharper at 

 tip; second joint of antenna shorter than first; rest wanting; mask large, 

 basal part strictly equilateral, produced in front in a very oblique angle ; 

 palpus equilateral ; movable hook short, thin, sharp. Prothorax short, not 

 exceeding the tubercles of hind angle; its sides bent up as triangular 

 knobs; wing cases large, long, reaching 8th segment; length of abdomen a 

 little greater than breadth, ovate; segments 7 to 10 roof-shaped, sloping; 

 side margin sharp; segments of equal length, except 10th, which is half as 

 long as 9th ; dorsal hooks on segments 2 to 10 ; on 2 and 3 long erected sharp 

 thorns ; on 4 to 9 compressed laterally, the very sharp tip bent backward ; 



