, 320 APPENDIX. 



3. D. sericeus. Entirely black, immaculate. 



Inhabits United States. 



% 9 ^orfy, particularly the venter d^nd feet, sericeous, 

 with short hairs ; wings dusky ; tergu7n glabrous, poKshed. 



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 resem- 

 bles Tenthredo unicolor, Beauv. but is somewhat larger, 

 the three last joints of the antennae are differently formed, 

 and the wings are dusky. 



EVANIA, Fabr. 



E. unicolor. Entirely black, immaculate, slightly seri- 

 ceous. 



Inhabits United States. 



Antennse as long as the body ; palpi piceous ; thorax 

 with very few, small punctures : metathorax densely punc- 

 tured ; wings hyaline, nervures fuscous; a distinct nervure 

 passes from the dividing nervure of the cubital and discoi- 

 dal cellules to the posterior margin of the wing ; abdo- 

 men much compressed, impunctured, polished, oval, rather 

 longer than the TpeXioXe,-, post ei^ior feet elongated. 



Length more than three-tenths of an inch. 



The proportions of the petiole, abdomen, and posterior 

 feet of this insect are nearly the same with those of ap- 

 pendigaster, Fabr. I obtained a specimen near the Rocky 

 Mountains, and it is also found in Pennsylvania. The ad- 

 ditional nervure is sometimes connected with the radial 

 cellule by a faint, transverse nervure, so as to form a second 

 cubital cellule. 



