6 ODONATA. 



Body long, narrow. Head cordate. Eyes large, prominent. Ocelli 

 developed. Antennae, somewhat shorter than head, two basal johits 

 short, globular; 3d twice as long as two preceding, dilated, bent in- 

 ward at tip, 4th joint rudimentary. Vertex flat ; outside of ocelli 

 are visible small tubercles, apparently where the spines of imago are 

 placed. Mask extending to fore legs, somewhat longer than broad, 

 channelled in middle ; fore-border a little broadest, cut straight ; 

 middle 3d with comb of short hairs. . Palpi short, strong, arcuated ; 

 tip forming strong bent hook, denticulated just before the end ; mov- 

 able hook as long as palpus, shar]^. Prothorax somewhat smaller 

 than head, nearly square, narrowed a little in front, sides and angles 

 rounded ; two flat impressions near the front and hind borders. Wing- 

 cases nearly reaching the 4th segment. Legs short, strong, hairy. 

 Hind legs more separated at base ; fore and middle legs of equal 

 length, shorter than hind legs ; femora very short, bent ; tibiae simi- 

 lar and longer ; tarsi nearly ^ as long as tibiae, 2-jointed ; claws bent ; 

 the outside claw shorter and stronger than inner one. Hind legs 

 reaching fith segment, nearly straight, tarsi 3-joiuted ; basal joint 

 short, two othei's of about equal length. Legs formed for burrowing. 

 Abdomen somewhat conical, tapering. Segments 1 to 8 nearly equal 

 length. 9th nearly twice as long, narrowed in middle ; 10th short and 

 slender; large flat spots on .segments 2 to 8 ; segments 6 to 9 with 

 lateral spines. No dorsal hooks. Anal appendices as long as 10th 

 segment, pyramidal, tlie two lower broader, not very sharp. All of 

 equal length and like shape. 



Male n^-mpha has sexual parts visible on 2 and 3 ventral segments ; 

 the opening of sexual parts on middle of 9th ; in the female a bifid 

 knob on the articulation between 8 and 9 is visible. 



9. Progomphus ? ? species. 



Selts, Monogr. (les Goniph., p. 194. 



Plate H., fig. 3, a, b, c. 



Nympha, full grown male and female. Length, 30 mm. ; breadth, 

 7 mm. Looks rather like ^Eschna. 



Locality : Wareham, Mass. Mus. Comp. Zool. 



Head stout, rather square, narrowed forward. Eyes not very promi- 

 nent. Ocelli very well developed. Vertex flat, with irregular hairy 

 spots. Antennae stout, two basal joints small, globular, 3d long, dilated, 

 very hairy, 4th small, ^ length of 3d, cylindrical, recurved. Behind 

 each eye a circular elevated spot, and between these, two impre.s- 



