234 EDWARD NORTON. 



deeply notched, labrum small ; mandibles sharp, with three or four in- 

 ner teeth. 



Tliorax punctured. Abdomen smooth and shining, stout, carinated 

 and acute in the females, obtuse in the males. 



Legs short; tibiae with two short spurs, the inner spur of anterior 

 pair bifurcate; claws with an inner tooth. 



Larvse, twenty-two-footed, (six pectoral, fourteen abdominal and two 

 caudal), not ejecting a fluid from the sides of the body. Little is 

 known of their habits. 



Leach separated, under the name of Doni/theus, all those species hav- 

 ing the third joint of antennae longer than the fourth, while his Dole- 

 riis has the third and fourth joints of equal length. Stephens adds that 

 Dosythoi invariably have bright colors on the abdomen, while the Do- 

 leri are of one color — blue and black. 



Hartig does not consider this, with minor details, a sufficient gene- 

 ric distinction, and his view has been adopted in the following list. In 

 all of our species, the third joint is longer than the fourth, although 

 the difference is less marked in the dark-colored species. 



Tahle to assist in finding tlie Species. 



A. Violaceous. 



«. Wholly of one color unicolor. 



6. Thorax partly rufous arvensis. 



B. Black. . 



a. Wholly black sericeus. 



b. Thorax partly rufous, abdomen black collaris. 



c. Thorax black. 



1. Abdomen red banded. 1. Femora black aprilis. 



2. Femora rufous apricus. 



3. Femora rufous, mouth and te- 



gulfe white albifrons. 



2. Abdomen wholly rufous abdominalis. 



d. Thorax partly rufous. 1. Abdomen red banded similis. 



2. Tergum red banded maculicollis. 



C Rufous. 



c. Thorax partly rufous, abdomen rufous bicolor. 



versa. 

 /. Thorax, except the pectus, rufous, abdomen rufous Tejoniensis. 



Section 1. — Dolerus. 

 Lanceolate cell with oblique cross line. 

 1. D. unicolor. 



Tenthredo unicolor, Beauv., Ins. Afr. et Am. ISO.j, 97. Ilym. Tab. ix, 2. % . 

 Dolerus unicolor, Lepel, Mon. Tenth. 125, 37.">. 



Norton, Bost. Proc. viii, 154, 9 • 

 Blue-black, with metallic reflections on the thorax. Length 0.2S. Br. wings 

 0.(50 inch. 



