398 PROCEEDINGS OP THE ACADEMY OP 



black, glabrous ; the rest of the mouth pale semi-transparent brown ; back part 

 of the head black, polished, without any hair next the eyes. Thorax covered 

 with dense, long, pale brown hair; the space included in the double edge of 

 each posterior bifurcation of the dorsal carina, bright yellow; no indications of 

 any stripes on the dorsum; pleura with a distinct yellow stripe enclosing the 

 spiracle ; sternum pale brown. Abdomen inflated at base to the middle of joint 

 three, thence much compressed and carinate above, pubescent, black, except 

 joint one and the basal half of two, which are pale brown ; two with a marginal 

 yellow spot on each side underneath at its base, and a yellow medial transverse 

 line, interrupted slightly above, beneath much abbreviated; 3 6 each with an 

 elongate, semi-oval, yellow spot on each side the dorsum, the straight side of 

 the spot on the medial suture, and the spot itself covering two-thirds the dis- 

 tance from the suture to the base of the joint; seven with a dorsal semieircular 

 basal spot extending to the medial suture, and confluent at its extreme tip, with 

 a similar but very much smaller yellow spot immediately behind the suture; 

 laterally three has a lanceolate basal and marginal yellow spot extending two- 

 thirds of its length, and four and eight have a small, obscure, basal, triangular 

 yellow spot ; venter black, so far as visible. Abdominal appendages a little 

 longer than the tenth abdominal joint, black, rather slender, depressed, directed 

 downwards, suddenly curving on their inner edge to an acute point, each sur- 

 mounting a semicircular, black anal process as long as itself. Vulvar lamina 

 black, very small, composed of two very small, approximate, roundish tubercles, 

 from which proceed two robust, widely divaricate, medially inflated branches, 

 convex in front, concave behind, and with a blunt, subbasal tooth on their pos- 

 terior edge. Legs black; coxae and trochanters pale brown, except the anterior 

 trochanters, which are distinctly yellow on their inferior surface. Wings hya- 

 line, strongly flavescent at their extreme costal base, and moderately so on 

 their terminal third, the flavescence in the anterior wing extending inwardly 

 along the costa beyond the nodus; a distinct ferruginous stripe between the 

 costal and subcostal veins, extending from the base of each wing nearly to the 

 first cross-vein ; veins and cross-veins black, except the upper of the two veins 

 which coalesce to form the costal, which in the lower wing, from a little inside 

 the nodus to the tip of the pterostigma, is yellowish anteriorly; membranule 

 white, cinereous at tip ; pterostigma trapezoidal, black. Triangles with one 

 cross-vein, in one posterior wing with two. Antecubitals 18 ; postcubitals 9 

 10. Two discoidal areolets, commencing with three, except one anterior wing 

 where it commences with two. 



Length $ 64 mill. Alar expanse 9 1 mill. Hind femur 12 mill.; hind 

 tibia 11 mill. Pterostigma 3 mill. One $?j c? unknown. Abdominal joints 

 4 6 are equal ; seven is about a fifth shorter than six, and 8 10 each about a 

 third shorter than the joint immediately preceding it, ten being about one and 

 a half millimetres long. The hind legs extend to the middle of the fifth abdo- 

 minal joint. Very distinct in its ornamentation from all the described N. A. 

 species, except pacifica, Hagen, of which only a fragmentary specimen exists, 

 and sufficiently distinct from that by the greater number of its antecubitals, 

 (eighteen instead of sixteen,) but especially by the coloration of its wings. 



Macromia flavipennis, n. sp. $ Differs from the preceding as follows: 

 the front above is entirely yellow, except a broad, fuscous vitta in the excava- 

 tion. Each side of the dorsum of the thorax there is a yellow stripe. Joint two 

 of abdomen has a subbasal, yellow fascia, extending on the inferior margin to 

 the tip, narrowly interrupted above, and occupying one-half its surface ; in joint 

 three the spot is similar to that of the preceding, but longer; 4 7 marked as 

 is seven in the preceding, and eight with a basal, semicircular spot on the dor- 

 sum, occupying nearly one-half its length; laterally the small, obscure, basal 

 spot is visible only in eight, instead of 4 and 8. The vulvar lamina is appa- 

 rently composed of one large central tubercle, and two robust, inflated branches 

 curving upwards. The wings are entirely flavescent, very strongly so on the 



[Sept. 



