14 PROCEEDINGS OF THE NATIONAL MUSEUM. tol. 60. 



14, 1904, A. A. Girault (U.S.N.M.). The species has been recorded 

 also from Florida. 



BIBIO SLOSSONAE Cockerell. 



BiMo slossotuie Cockebelx (T. D. A.), Fossil Insects from Colorado, The 

 Entomologist, vol. 42, p. 174, July, 1909. New name for B. gracilis 

 Walker, 1848, not of Unger, 1841. 



Bibio gracilis Walker (Francis), List Dipt, Ins. Brit. Mus., vol. 1, 1848, p. 

 123 [Nova Scotia]. 



Male. — With head and body black, the head and thorax with 

 copious long black hair, abdomen with the same, gray ; legs brown to 

 black, joints having a tendency to be pale basally and dark apically, 

 the coxae and femora long haired, slender, the posterior elongate, 

 hind femora and tibiae clavate, hind tarsi enlarged; spurs of front 

 tibiae very unequal, rufous; wings hyaline with a slight yellowish 

 cast. 



Female. — The female differs by all the hair being short and pale 

 and the pleura, coxae, and succeeding leg joints (except for faint dark 

 tips) yellowish rufous; wings a little more deeply suffused with yel- 

 lowish brown ; stigma and anterior veins in both sexes brown. 



Length of wing, 5-6.5 mm. 



Specimens examined are from Unalaska, Ontario, Maine, New 

 Hampshire, Massachusetts, Maryland, and Arizona. Only males 

 have been identified. Is this form merely a dimorphic male of B. 

 longipes Loew? 



BIBIO TENUIPES Coqnillett. 



BiJiio tetmipes Coquillett (D. W.), New Diptera from North America, 

 Proc. U. S. Nat. Mus., vol. 25, p. 95, Sept. 12, 1902 [Williams, Arizona]. 



Head and body black, narrow, humeral ridge pale yellow ; hair of 

 eyes of male black, hair elsewhere in both sexes pale yellow to gray- 

 ish, shorter on female; legs dark reddish brown, the front tibial 

 spurs rufous, very unequal, hind legs but little longer than others, 

 joints scarcely clavate, first joint of hind tarsus but little longer 

 than second; wings sordid hyaline, all the veins brown. Length of 

 wing, 4-7 mm. 



Specimens examined include the type from Williams, Arizona, 

 June 5, H. S. Barber, and numerous others from Las Vegas, New 

 Mexico, May 4, 1904; Santa Fe, New Mexico, May 6, H. S. Barber; 

 Boulder, Colorado, May 22, 1907, S. A. Rohwer (U.S.N.M.). 



BIBIO TRISTIS Williston. 



Bibio tristis Williston (S. W.), in Kellogg, V. L., Insect Notes, Trans. 

 Kansas Acad. Sci. (1891-2), 1893, pp. 113-14 [Western Kansas]. 



Male. — Head, body, and coxae black with boderately long black 

 hair; femora and succeeding leg joints, rufous, tipped or more ex- 



