22 PROCEEDINGS OF THE NATIONAL MUSEUM vol. G8 



length and width of the first abdominal segment is rather a variable 

 and unreliable one in this group. 



Originally described from Nevada. The specimen I assign here 

 is from Luna, N. Mex., June, 1916 (J. G. Crick). 



BRACHYCISTIS (BRACHYCISTIS) GLABRELLA Cresson 



Originally described from Colorado. I have specimens evidently 

 belonging to this species from Arizona, Texas, New Mexico, Colorado^ 

 and South Dakota. 



One specimen from Texas is only 7 mm. in length; the average 

 length of the series is over 10 mm. 



ATRATA group 



Characters. — This group has the gular carina elevated and de- 

 flected at or near the anterior extremities, the highest points visible 

 below the mandibular condyle when the head is viewed directly 

 from the side, or if the elevation is barely or not visible the vein eman- 

 ating from the apical costal angle of the stigma turns downward at 

 less than the length of the cross vein emanating from hind side of the 

 stigma from apex of latter. 



KEY TO SPECIES 



1. Gular carina ver\' low, not elevated at anterior extremities, not visible below 



condyle from side, distance from anterior extremity to condyle about half 

 as great as anterior width of gular orifice; mandible distinctly angulate near 

 base; propodeum rounded, microscopically shagreened dorsally, and with 

 very faint sulcate line from anterior margin; the vein emanating from apical 



costal margin of stigma bent downward at base imitans, new species. 



Gular carina more or less distinctly elevated and outwardly deflected at or 

 near anterior extremities, frequently visible below condj'le when head is 

 seen from the side, and not so far distant from condyle 2, 



2. At least the head and thorax shining black 3. 



Thorax brownish orange or castaneous, head sometimes black above 5. 



3. Central tubercle on clypeus very prominent; anterior extremities of gular 



carina vertical, not flared outward, distant from mandibular condyle by 

 three or four times the width of apical segment of maxillary palpus; vein 

 emitted from apical costal angle of stigma paralleling costa for a short dis- 

 tance before bending downward; propodeum granulose or rugose at the edge 

 of the rather vertical posterior portion, dorsum with a quite pronounced 



median longitudinal sulcus lacustris, new species. 



Central tubercle on clypeus poorl}- developed; anterior extremities of gular 

 carina flared outward, usually quite distinctly visible from side 4. 



4. Dorsal surface of propodeum entirely, or for the greater part, obviously 



shagreened, and not highly polished; abdomen more brown or reddish- 

 brown than black; frons in front of ocelli with scattered punctures, no large 



one in front of anterior ocellus semlatra, new species. 



Dorsal surface of propodeum highly polished and smooth except for the faint 

 median longitudinal sulcus; abdomen normally entirely black; frons in 

 front of ocelli polished, almost impunctate except for a large, deep pit or 

 puncture just in front of anterior ocellus atrata (Blake.) 



