214 long's second expedition. 



Length one-fourth of an inch. 



This species belongs to Dolerus ff of Le Pelletier, Emphyins 

 Leach. 



2. D. ARVENSIS. — Blackish-violaceous ; thorax rufous, a spot 

 before and triangular spot behind, black. 



Inhabits LTnited States. 



5 Antennae black; palpi and mandibles black; head black 

 with a violaceous tinge ; thorax with a longitudinal spot from the 

 collar to the middle, a small spot over the wing, posterior margin 

 connected witlKa spot, black ; metathorax black ; wings dusky ; 

 pleura and pectus black, tinged with violaceous, the former rufous 

 at the humerus, this color being connected with that of the thorax; 

 feet black ; abdomen dark-violaceous. 



Length more than seven-twentieths of an Inch. 



Var. a. Black spot above the wing enlarged and reaching the 

 dorsal spot. 



This species belongs to Ili/Iofoma Fabr., Dosi/thaeus Leach, 

 and Dolerus ff Le Pelletier. It is found in the North-west 

 Territory, Pennsylvania, and Arkansa. This species is closely 

 allied to Tenthredo thoracina Beauv., but it does not fully agree 

 with his figure, and his description is too unessential to be 

 useful. [320] 



3. D. SERiCEUS. — Entirely black, immaculate. 

 Inhabits United States. 



% 9 Body, particularly the venter and feet, sericeous; with 

 short hairs ; wings dusky ; tergum glabrous, polished. 



Length seven-twentieths of an inch. 



Belongs to the same division with the preceding species. 



It is found as far south and west as Arkansa. It resembles 

 Tenthredo nnicolor Beauv., but is somewhat larger, the three last 

 joints of the anteunse are differently formed, and the wings are 

 dusky. 



EVANIA Fabr. 



E. UNICOLOR. — Entirely black, immaculate, slightly sericeous. 



Inhabits United States. 



Antennae as long as the body; palpi piceous ; thorax with very 

 few, small punctures; metathorax densely punctured; wings 

 liyaline, nervures fuscous; a distinct nervure passes from the 



