82 HENRY L. VIERKCK. 



fluoiis. Area refers to the enclosure on the disc of the metathorax 

 always present, tliough sometimes much abbreviated. P'elt lines, 

 mean the furrows or impressed lines, filled with appressed pubes- 

 cence, thus »». Subtle area is an enclosure on the second abdo- 

 minal segment, sometimes hidden by the overlying first segment. 



The species are rare in collections. During several weeks of lamp 

 light collecting at Alamogordo, New Mexico, only one specimen was 

 captured. Only one specimen is on record oi' vetiiistus, auhu^, adonis, 

 thamyras, mellicausa and clandeslinus. Unless otherwise stated, the 

 specimens on record, in this paper, are to be found in the collection 

 of the American Entomological Society and the Academy of Natural 

 Sciences, Philadelphia. For the privilege of examining specimens 

 in the United States National JNtuseum collection, I am indebted to 

 Dr. W. H. Ashmead. 



Key to the Species. 



Head bulged behind the eyes, quite quadrate ; large species 1. 



Head more triangular, sloping behind the eyes 3. 



1. Process of niesosternura large, heavy, gradually fusing with the niesosteruum, 



mandibles terminating in a flattened angled portion. 



venusttis (Blake). 

 Process of mesosternum a short sharp tooth or spur, mandibles not very dis- 

 tinctly flattened near the end, straight 2. 



2. First abdominal segment rather coarsely punctured and closely, legs dark. 



tapajiis (Blake). 

 First segment with small rather sparse punctures, legs light- -aiilUM (Blake). 



3. First segment slender, not very bioad at apex, a distinct constriction between 



it and the next segment 12. 



First segment broad, very broad at apex, sessile, no distinct constriction.. .4. 



4. Large species, with a pygidial area bounded by a sharp ridge; In mm. 



adonis (Fox). 

 Pygidial area poorly defined or absent ; 13 mm. long or less .5. 



5. Species 8 mm. and over, processes strong ... .6. 



Species 8 mm. and less, processes weak 7. 



6. Last segment with a poorly defined pygidial area, insect dark testaceous. 



in«'Oii!«|>icuiis (Blake). 

 Last segment without a pygidial area ; insect pale testaceous. 



acinseiis n. sp. 



7. Processes formed by the mesosternum being produced into a more or less pro- 



nounced angle on each side of the media furrow, anteriorly the pro- 

 cesses are nearly contiguous, species dark 8. 



Processes simply short, sharp teeth, sjiecies pale 11. 



8. Strongly punctured throughout • • • sarpedoii (Fox). 



Moderately, rather sparsely punctured 9. 



