



Fosso7-iaI ITymenojitcra of Norlli America. 3C1 



Thyreopus signifer. n. sp. 



% . Head more cuboidal than in T. cribrellifer, being longer, and not 

 narrowing so rapidly behind ; the front less deeply excavated, eyes of 

 same size, ocelli arranged in a similar low triangle ; in front of them a 

 transverse line of hairs extending towards the insertion of the antennae. 

 Cljpeus as in T. latipes, a lateral line of silvery hairs along the front 

 edge of the eyes, as usual. Antennae simple, joints cylindrical, long 

 and slender, sutures well marked. 2nd joint a third longer than 1st or 

 3rd j joints showing a slight tendency to become flattened beneath; 

 black, scape yellow, black at base on upper side ; mandibles black, a 

 little yellowish at base. Prothorax above reddish-yellow, interrupted 

 in middle ; thorax much as in T. cribrellifer ; a reddish-yellow stripe on 

 scutellum ; hind edge of yellow tubercle very convex. 



Fore coxa), trochanters and femora black, tibia) expanded into a 

 broad concavo-convex, shield-like plate, as long as broad, sub-pentago- 

 nal, the angles much rounded, and the end obtuse, bein" angulated 

 near the middle of the posterior edge, and near the base of the anterior 

 edge; tibiae yellow, but the plate dark, with light lines radiating from 

 the middle of the tibiae, with other independent lines. Tarsi large, 

 well developed, fuscous; middle and hind femora black; tibiae yellow, 

 with an external dark mark, tarsi fuscous. Abdomen smooth and 

 shining as usual, yellow fascia) as in T. cribellifer, but they are broader 

 and heavier, not indented, the stripes being continuous across the ab- 

 domen on the 4th and 5th rings; edge of 6th ring obscurely yellow, tip 

 spatulate. a little hirsute. 



Length of body, .42; head and thorax, .20; abdomen, .22 inch. 



Brunswick, Maine. August, on flowers of Spiraea alba. 



Easily known by its short, dark, shield-shaped plate or vexhillum, 

 which is as broad as long, and the presence of a yellow band on the 

 meso-scutellum ; its simple non-expanded antenna), the fuscous yellow 

 spots on the thorax, and entire non-indented abdominal fasciae. It is 

 of the same size as T. cribrellifer, but a little shorter. 



9 . A female specimen received from Mr. Sanborn differs from the 

 Other sex by its shorter head, more deeply excavated front, and more 

 convex vertex ; the clypeus is longer, scape of antenna) more thicken- 

 ed, otherwise the color is the same. The thorax is sculptured and 

 spotted the same, but the enclosure of the propodeum is more deeply 

 furrowed and rugose on each side of the mesial furrow. Fore and mid- 

 dle legs colored as in T. pegasus, internal ring and two remote fasciae 

 one-half narrower than in T. pegasus, where they form a broad, scarcely 

 interrupted band; terminal band narrower, tip of abdomen a little 



PROCEEDINGS F.XT. SOC. PHILAD. FEBRUARY, 1867. 



