No. 39] ODONATA OF CONNECTICUT: PETALURIDAE I 17 



"Head : wide, angular, square, convex in front, concave behind, 

 the eyes placed in the outer anterior corners ; roughened, generally 

 sparsely hairy, edges and tubercles with dense bristle-like hairs; 

 on each side, back of the eyes, two prominent edges and a less 

 developed one above ; face in front of base of antennae vertical ; 

 antennae 3.5 mm. long, hairy, flattened, the basal joint largest, 

 terete, with the external edge angular; last joint small, apex irreg- 

 ular; other joints about equal in size, slightly larger basally, 

 about half as long as wide. Labium short and broad ; middle lobe 

 square, 4.5 mm. long and 5.5 mm. wide, abruptly narrower near 

 the posterior end ; anterior edge with a larger tooth on either side 

 of the median line and about ten smaller ones on either side ; 

 extending posteriorly to half way between the bases of the first 

 and second pairs of legs ; lateral lobes wide, opposed edges 

 straight, notched with small serrations. 



"Prothorax angular, high, dorsum and sides meeting at nearly a 

 right angle, the edge produced laterally and clothed with bristly 

 hairs ; all of thorax scantily clothed with short hairs. The thorax 

 widens and deepens from the prothorax to the metathorax at the 

 base of the third pair of legs where it is as wide as the abdomen 

 in its widest part. The front wing-cases extend to the posterior 

 edge of the fourth abdominal segment ; apparently the costas lie 

 almost parallel ; the cases of the hind wings reach to the middle 

 of the fifth segment. Legs very robust, strongly formed, angular, 

 especially the femora, the edges clothed with bristles ; a deep 

 depression in the mesosternum, between the second pair of legs 

 to accommodate the hinge of the labium. 



"Abdomen spindle-shaped, 23 mm. long, widest at the fifth seg- 

 ment where its width equals one-half its length, low, flattened, the 

 sterna scarcely convex, terga convex, width of fifth segment 11 

 mm., depth 5 mm. Segment nine with a lateral posterior spine; 

 on segments anterior this spine grows successively smaller, not 

 present on first three segments. The mark, on the sternum of 

 the ninth segment, of the ovipositor of the imago is conspicuous. 

 On dorsum of segment five are two tufts of bristles, one on either 

 side, separated from each other by about one-third the width of 

 the segment, and placed a little nearer the posterior than the 

 anterior margin of the segment; these tufts persist from the fifth 

 to the ninth segments, the tufts on each segment successively 

 approaching each other more closely till on the ninth they stand 

 just on either side of the median line ; each tuft is placed on an 

 irregular elevation and in some cases seems to be double. Appen- 

 dages short, middle one tapering ; apex truncate, on either side 

 produced to form a short tooth ; laterals shorter, conical ; inferiors 

 compressed, wide, rounded triangular, longer than the middle 

 appendage, the lower edges and the posterior ventral edge of the 

 tenth segment between them bearing many long stiff, yellowish 

 hairs. 



