1920] Melander: Nearctic TetanoceridcE 313 



Pteromicra melanothrix new species. 



Male — Length, 4 mm. Head, including mouthparts, thorax, 

 abdomen, front legs beyond basal three-fifths of femora, and apex of 

 hind femora black, shining on body, dull on legs, antennae, base of front 

 legs, posterior legs, halteres and calypteres yellowish, two white pruinose 

 occipital spots. Third joint of antenna rounded-quadrate, the arista 

 but slightly longer than the antenna, its basal joint thick and one- 

 fourth the length of the arista. Lower pleurse lightly white pruinose, a 

 faint indication of three brown-dusted vittae on mesonotum. Abdomen 

 with short pubescence, hypopygium globose. Front femora bearing 

 three small extensor bristles on apical half and hind femora bearing 

 two. Wings a little grayish, veins blackish, the anterior veins brown, 

 posterior crossvein slightly clouded, wijigs less than three times as long as 

 wide, widest opposite anterior crossvein, first vein ending beyond 

 anterior crossvein and at middle of wing, costal sections proportioned 

 1 : 1 : 2.5 : 0.9 : O.G, of fourth vein, 1 : 1 : L7. 



One specimen. Yellowstone Lake, Wyoming,* August 9, 

 1918. 



Pteromicra leucothrix new species. 



Length, 2-3 mm. Head, including mouthparts and third antennal 

 joint, and front legs between the basal three-fifths of the femora and the 

 apical two or three joints of the tarsi black, the body polished, base of 

 antennae, remainder of legs and halteres yellow, apical joints of front 

 tarsi and arista white, occiput not pruinose. Third joint of antennae 

 elliptical, the arista twice as long as the antenna, its basal joint short. 

 Lower pleurae very lightly pruinose. Front femora with three and hind 

 femora with two small bristles above toward apex. Wings nearly four 

 times as long as wide, widest opposite posterior crossvein, nearly hyahne, 

 veins blackish, second vein abnormally long, the costal sections pro- 

 portioned 1 : 0.6 : 6 : 1 : 0.6, sections of fourth vein, 1:1:2. 



Five specimens. Mount Constitution, Orcas Island, Wash- 

 ington,* July, 1919. 



Melina Desvoidy. {Sciomyza of authors).! 



Melina Desvoidy, Myodaires, 695 (1830). 



Arina Desvoidy, same, 696 (1830). 



Chetocera Desvoidy, same, 697 (1830). 

 Pherhellia Desvoidy, Myodaires, 696 (1830). 



Dvclia Desvoidy, same, 693 (1830). 



Ditcenia Hendel, Abhandl. z. b. Ges. Wien, II, 66 (1902). 

 Graphomyzina Macquart, Hist. Nat. Ins., Dipt. II, 558 (1835). 

 Atrichomelina Cresson, Tr. Am. Ent. Soc. XLVI, 40 (1920). 



Achatomelina Cresson, same, 30 (1920). 



t This dominant genus includes most of the species listed in Aldrich's Catalog 

 under Sciomyza. Of the several generic names proposed by Desvoidy, Dyctia 

 has page precedence, but because of its similarity to Dictya Meigen, of the same 

 family, the name Melina adopted by Hendel and Cresson, is here used. 



