58 D1PTERA OP NORTH AMERICA. [PART III. 



First longitudinal vein bristly upon its end only; fourth longi- 

 tudinal vein bent forward towards its end; posterior angle of the 

 anal cell not drawn out in a lobe. 



Rather robust species having the thorax pollinose with gray, 

 without stripes or with weak oues, a black, shining abdomen, 

 generally with gray bands, and wings which have black cross- 

 bands, or spots almost forming such crossbands. 



Typical species : urticae. Lin. 



14. Holodasia Lw. 

 Charact. — Third antennal joint distinctly excised on its upper side. 



Thorax without bristles upon its middle, in front of the region 

 of the suture. 



First longitudinal vein bristly upon its whole length ; fourth 

 longitudinal vein curved forward at the end ; posterior angle of the 

 anal cell not drawn out in a point. 



Holodasia differs from Anacampta (which it otherwise re- 

 sembles very much) in the fact that the first longitudinal- vein is 

 bristly upon its whole extent, and not upon its end only. In this 

 it agrees with Pteropoecila, from which it differs in the not pro- 

 jecting front, longer antennae, the third joint of which is excised 

 upon its upper side and pointed at the tip and in the fourth longi- 

 tudinal vein being curved forward. 



Typical species : fraudulosa Lw. 



Fifth Section: Pterocallina. 



At the beginning of the chapter on the Systematic Distribution 

 of the Ortalidae, I have pointed out Scaiophaga fasciata as the 

 species of this group known for the longest time and which may 

 be considered as typical. It was described under that name by 

 Fabricius in the Systema Antliatorum, was transferred by Meigen 

 to the genus Trypeta and by Robineau Desvoidy to his new 

 genus Myennis. It is very probably the same fly which was 

 described by Coquebert in his Iconographia, Dec. Ill, under the 

 name of Musca octopunctata, although it has nothing of the 

 picture of the thorax shown in Coquebert's figure and which gave 

 rise to the specific name. Although the publication of Coque- 

 bert's name is probably a little anterior to that of Fabricius, the 

 choice of this name, based upon a non-existing character, as well 

 as the nature of the entomological correspondence, which existed 



