Fossorial llymenoptera of North America. 417 



posteriorly ; with a slight mesial ovate depression, hirsute on the sides; 

 tegulae reddish testaceous, wings slightly clouded on the outer edge, 

 distinctly iridescent. Legs black, slightly sericeous, basal joints of 

 the tarsus pale fuscous at base, especially at the posterior pair, tips 

 brown-black. Abdomen long and slender; on the 3d and succeeding 

 joints rather suddenly clavate, more so than in the other species; two 

 basal joints very slender and long, above mesially grooved, entirely 

 black, basal half of 2d ring red; tip acute, raised mesially, one-third 

 longer than head and thorax. 



Length, .40 — .48; head and thorax, .20; abdomen, .28 inch. 



Delaware, (Ent. Soc. Phil.). Virginia, (Norton). 



Its narrow front, which is more sparsely punctured than usual, its 

 excavated, slightly bilobate elypeus, the much more finely striated pro- 

 podeum, and the more suddenly clavate abdomen, with the narrow red 

 ring on the basal half of the 2d ring, and its smaller size, will suffi- 

 ciently distinguish this species from T. tridentatum. 



Trypoxylon tridentatum, n. sp. 



9 . Head closely resembling that of T. rubro-cincfum, front wider 

 and more finely punctured, and the pubescence and interantennal bi- 

 carinate protuberance the same ; elypeus tridentate on anterior edge, 

 towards which the surface is raised, and there is a slight mesial carina 

 which is deeply excavated, thus giving a bilobate form to the edge, 

 while the end of the mesial carina, projecting out sharply, gives a bi- 

 deutate appearance when seen from above. Thorax as in the preced- 

 ing species, finely pubescent, thicker on the sides. Propodeum with a 

 shallow semi-elliptical depression, large and swelling sides, with very 

 regular, parallel, curvilinear striae, curving from the base, and arcu- 

 ated on the swollen sides; the striae become coarse on the flanks, and 

 are doubled obliquely forwards; posteriorly, the mesial line is much 

 smaller than in preceding species, being linear. Wings dusky on the 

 outer border, nervules black, not so iridescent as in T. rubro-cinctum. 

 Legs black, hind tarsi black-brown, sericeous, with the tips of the joints 

 narrowly dark testaceous. Abdomen much thicker at the base, more 

 regularly clavate than in the preceding species; terminal third of the 

 basal, and the entire 2d joint bright red, remainder black; tip as in 

 the preceding species. 



Length, .44; head and thorax, .20; abdomen, .24 inch. 



New York, New Jersey, (Norton). 



Its more filiform antennae, tridentate elypeus, broader front, and pe- 

 culiar striation of the propodcuni, the black tarsi and broad band of 



PROCEEDINGS ENT. SOC. PHILAD. FEBBUABT, 1S67. 



