6 ODONATA. 



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

 developed. Antennas, somewhat shorter than head, two basal joints 

 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 longe % r 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, sharp. 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 ; tibia? 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 6th segment, nearly straight, tarsi 3-jointed ; basal joint 

 short, two others 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, the two lower broader, not very sharp. All of 

 equal length and like shape. 



Male nympha 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. des Gomph., p. 194. 



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



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

 7 mm. Looks rather like iEschna. 



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



Head stout, rather square, narrowed foi'ward. Eyes not very promi- 

 nent. Ocelli very well developed. Vertex flat, w T ith irregular hairy 

 spots. Antenna? stout, two basal joints small, globular, -3d long, dilated, 

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

 each eye a circular elevated spot, and between these, two impres- 



