INSECUTOR INSCITI^ MENSTRUUS 33 



Differs from Cylindromyia by the swollen abdomen, and 

 venter of second and third segments of female covered with 

 very short sharp tubercle-like spines directed backward. Facial 

 plate with very prominent carinal tubercle on upper part. 

 Claws of male long. Hind crossvein oblique, sinuate. Arista 

 not incrassate at tip in either sex. Second aristal joint slightly 

 elongate in male. 



The holotype was from Nova Scotia, and the species is mod- 

 erately common in New England. 



TANYPEZID^ IN THE UNITED STATES 



(Diptera acalyptrata) 

 BY FREDERICK KNAB and R. C. SHANNON 



As far as we are aware, this interesting group of acalyptrate 

 Diptera has not hitherto been reported from temperate North 

 America. Two species from this region, both new to science, 

 are described in the following. The group is of special inter- 

 est to systematists on account of the somewhat obscure rela- 

 tionship and consequent difference of opinion as to the correct 

 position in the system. Most frequently the genus Tanypeza 

 appears as a member of the family Micropezidas, where we 

 find it in the Aldrich catalog (1905). Williston, in his Manual 

 of North American Diptera (3d edit., 1908, p. 264), treats 

 Tanypeza together with the Micropezidse, but insists that it 

 represents a separate family, without, however, entering into 

 the question of relationships. In 1903 Friedrich Hendel dis- 

 cussed the Tanypezidse and showed that the resemblances with 

 the Micropezidae are purely superficial.' He assigns the group 

 to the Ortalidae, giving it the same rank as the other sub- 

 families.' We believe that Mr. Hendel's opinion is well 



'Ueber die systematische Stellung von Tanypeza Fall. Wien. Ent. 

 Zeit., vol. 22, pp. 201-205. 



*Mr. Hendel considers the Ortalidae as of merely subfamily rank 

 in the "Muscaria," and adopts the term "section" for our customary 

 subfamilies. 



