344 BULLETIN UNITED STATES GEOLOGICAL SUEVEY. [TolY. 



Stizus IFogardii Cress., Proc. E. S. P. ir, 145, ^ 9 (1865). 

 SfAzus Hogardii Pack., Proc. E. S. P. vi, 443, $ (1867). 

 Hogardia rufescens Lepel., Hym. iii, 289, t. 28, f. 5, $ (1845). 

 Eogardla rufescens Guer., La Sagra's Hist. Cuba, vii, 320 (1857). 



Habitat: Cuha, St. Domingo. 



4. Sphecius SPECTABILIS. 



yS<i^MSsj)ecte&i;isTascli.,Zeit.ges.Nat.xlv,360, $ $ (1875). 



Habitat: Brazil. 



Group. STIZI. 



Marginal cell ovate-lanceolate, not extending as far as the third sub- 

 marginal cell. Submarginal vein not flexed to meet the first recurrent 

 nervure ; the first recurrent nervure curved at the apex and inserted at 

 an angle. Submedial cell of posterior wings terminated by a straight 

 transverse nervure. 9 , Spurs of posterior tibiae not dilated, reaching 

 only to the middle of the first tarsal joint. ^ , Three spines, or only one, 

 at the apex of the abdomen; the sixth ventral segment transverse; 

 lileural lobes of the seventh segment separated by an incision and a 

 suture from the tergum. 



Megastizus n. g. • 



Type : Stizus Irevipennis Walsh. 



Eighth ventral segment of the male forming a broad, tridentate spine. 

 Basal joint of intermediate tarsi not dilated and not excavated. Labrum 

 with its length not half as great as its breadth. Submedial cell of the 

 posterior wings narrow, extending no more than its own breadth beyond 

 the origin of the transverse medial nervure. — Head well rounded out 

 behind the eyes; axes of the eyes parallel, the inner margin very 

 slightly excavated above. Face broader than in Sphecius; clypeus 

 transverse, hexagonal, the upper side straight, the lower side excavated. 

 The piece between the clypeus and the antennge longer than in Sphecius, 

 but not keeled as in Stizus. Mandibles short and stout, very unequally 

 bidentate. Antenn ce slender, thickest at the ninth J4)int, which is shorter 

 than any other excepting the second ; third joint arcuated, as long as 

 the fourth and fifth taken together. The antennae of the male unarmed, 

 the apical joint slender like the preceding joints, much excavated 

 beneath, the apex subtruncate ; the antennae not grooved and not pitted 

 beneath ; longer than in the female. Body robust, abdomen of the male 

 elongate and surpassing the wings. Thorax short, metathorax vertically 

 truncate; the base of the abdomen subtruncate and sessile. Legs stout, 

 the pulvillus large. Anterior tarsi short, joints two to four transverse ; 

 anterior tarsi of the female shghtly dilated exteriorly, but the joints not 

 produced at the tip, fringed externally with spines equalling the fifth 

 joint in length. Intermediate tarsi simple in both sexes, strongly 

 spinose in the female. Spurs of the posterior tibiae not half as long as 

 the first tarsal joint. Sixth dorsal segment of the female suddenly nar- 



