1916] American Species of Xylocelia 351 



mandibles, except the tips and posterior lobes of the pronotum yellowish; 

 tegulag and anterior tibise in front testaceous. 



cf . Unknown. 



Type: A female collected in Monroe Canyon, Sioux 

 County, Nebraska, August 19, 1912 (R. W. Dawson). Related 

 to striatus, but is smaller, more slender, has the propodeum 

 sculptured differently and the posterolateral angles of the 

 propodeum not produced. 



Xylocelia nigritus Fox. 



1892. Diodontus nigritus Fox, Trans. Amer. Ent. Soc, xix, p. 317. 



Type locality: Colorado. 

 Xylocelia adamsi Titus. 



1908. Diodontus adamsi Titus, Ecology of Isle Royale, Michigan Survey,^ 

 p. 319. 



The following description is drawn from the type specimen 

 kindly loaned the writer by Dr. E. G. Titus. 



9 . Length 7.1mni. Labrum deeply and angulately emarginate, 

 the teeth formed by the emargination acute; front with strong, rather 

 close punctures, finely granulate between the punctures; median 

 impressed line of front faint; vertex, occiput and cheeks punctured like 

 the front; (antennae missing in the type); mesoscutum with strong, 

 rather close punctures, denser on the anterior and posterior margins; 

 suture between the mesoscutum and mesoscutellum foveolate; mes- 

 oscutellum distinctly punctured; episterna coarsely reticulate anteriorly, 

 obliquely rugose posteriorly; upper surface of propodeum coarsely 

 reticulate; posterior face of propodeum coarsely reticulate, supra- 

 medially with a large, pentagonal enclosed area; sides of propodeum 

 with a few, coarse rugae; abdomen microscopically punctate; pygidium 

 triangular, about one and one-fourth times as long as wide, strongly 

 punctured on the basal half; wings hyaline, stigma black, nervures 

 yellowish testaceous. Black; tegulae brown, yellowish anteriorly; 

 all the tibiae and tarsi reddish brown, more or less testaceous beneath. 



cf . Unknown. 



Type: A female collected at Isle Royale, Michigan (Adams). 

 Related to nigritus^ but the sculpture of the propodeum, 

 coloration of anterior wing veins, and of the tibiae and tarsi, are 

 different. 



Xylocelia ater n. sp. 



9 . Length 6-7mm. Labrtmi large, deeply and angulately emargi- 

 nate ; lower portion of front tending to be striato-punctate ; upper portion 

 of front fairly closely and shallowly punctate; median impressed line 



