ART. 11. FLIES OF THE FAMILY CLUSIIDAE MELANPER AND ARGO. 5 



1. Genus ACARTOPHTHALMUS Czerny. 



Acartophthalmus Czerny, Wien. ent. Ztg., vol. 21, p. 256 (1902); vol. 22, p. 71 

 (1903). 



Eyes provided with very fine scattered hairs; arista but little 

 longer than antenna; postverticals strong and widely spaced; no 

 cruciate frontal bristles, ©cellars long, three fronto-orbitals, the 

 foremost small and reclinate; pro thoracic seta wanting, three post- 

 sutural dorsocentrals, no prescutellars, four scutellars, the basal 

 pair strong; no preapicals; crossveins widely distant. 



Genotype. — A. nigrinus Zetterstedt. This is the only genus having 

 pubescent eyes, but this character requires high magnification to be 

 detected. It is unique further in having a short arista, distant 

 postverticals and a humeral break in the costa. Two species are 

 known. 



KEY TO THE SPECIES OF ACARTOPHTHALMUS. 



Body black, legs brown or black, the front coxae somewhat paler; wings hyaline. 



(Europe, N. Amer.) nigrinus Zetterstedt. 



Face, cheeks, anterior part of front, antennae, and mouthparts yellow; legs yellowish; 



wings infuscated anteriorly. (Europe.) bicolor Oldenberg. 



1. ACARTOPHTHALMUS NIGRINUS Zetterstedt. 



(Fig. 10.) 



Anthophilina nigrina Zetterstedt, Dipt. Scand., vol. 7, p. 2697 (1848). 

 Acartophthalmus nigrinus Czerny, Wien. ent. Ztg., vol. 22, p. 71 (1903). — 

 Malloch, Proc. Ent. Soc. Wash., vol. 20, p. 3 (1918). 



Entirely blackish, the front coxae and halteres alone yellowish. 

 No distinct vibrissae, about six uniform buccal bristles present; 

 arista weakly pubescent, scarcely exceeding the length of the antenna, 

 the basal joint thickened. Basal scutellar bristles about half the 

 length of the convergent apical pair. Hypopygium very small. 

 Wings grayish hyaline, auxiliary vein distinctly separated from the 

 first vein, costal ratio, 3.8:1.4:1, sections of fourth vein 1:1.5, of 

 fifth vein 3:1. Length 2 mm. 



Distribution. — Tw'enty-two specimens, collected by Melander, from 

 Petersham, Massachusetts; Moscow Mountain and Waha, Idaho; 

 Wawawai, Olga, Mount Constitution, Quilcene, Blewett, Vashon, and 

 Tacoma, Washington. Compared with a specimen from Admont, 

 Austria, received from Prof. G. Strobl. Recorded from Sweden, 

 Germany, and Austria. 



2. ACARTOPHTHALMUS BICOLOR OldenberK. 



Acartophthalmus bicolor Oldenberg, Deut. ent. Zts., 1910, p. 284 (1910). 



Lower part of head, antennae, anterior margin of front and legs 

 yellowish; costal margin of wings infuscated; length 2 mm. 



Habitat. — Germany. Type in collection of L. Oldenberg, Berlin. 



