HORSEFLIES OF THE SUBFAMILY TABANINAE 31 
Type locality—Carolina Beach, N. C. (Published as “California 
Beach”). 
Distribution.—North Carolina, April 7 (Southern Pines) to April 
20 (Carolina Beach). 
The Genus STENOTABANUS Lutz 
Stenotabanus Lutz, Brazii-Medico 27 (45) : 487, 1913; Mem. Inst. Oswaldo Cruz 
6: 167, 1914; Enderlein, Mitt. Mus. Zool. Berlin 11: 354-355, 1925; Krober, 
Enc. Ent. Dipt. 5: 113-114, 1929. (Genotype, Tabanius taeniotes Wiedemann.) 
Styposelaga Enderlein, Mitt. Mus. Zool. Berlin 10: 548, 1922; 11: 342-3438, 1925. 
(Genotype, Styposelaga sexannulata Enderlein. ) 
Generic characters.—Rather small, slender; third antennal segment with 
scarcely any dorsal angle and no excision; eye bare or sparsely pilose; a small 
ocellar tubercle or denuded spot at vertex present or absent; first antennal 
segment not swollen; base of vein Rs usually with a rather long stump vein. 
Considering the Nearctic species alone, it would appear that psam- 
mophilus (Osten Sacken) and related forms should be considered at 
least subgenerically distinct from the more typical favidus (Hine). 
The Neotropical species, however, longipennis Krober and guinque- 
striatus Krober, form connecting links that would seem to prohibit 
separation of the genus into clearly defined groups. Most of our 
species have taken to an ocean beach or desert environment, with a 
consequent graying or whitening of color. 
Key to Nearctic Species of Stenotabanus 
1. Frons of female more than four and one-half times as high as width at 
basal callus; brown species with one or three rows of pale spots 
CONNER G1 O10 Cie eens oe ENS NS ED Pe ea es 2 
Frons of female four or less times as high as width at basal callus; 
SCANS OLY Sy OTE ES) PTT Ee ee ee eee ae 3 
2. A distinct ocellar tubercle; abdomen with a single median row of gray 
[eH EAM eS ss Si a re ee flavidus (Hine), p. 31. 
No ocellar tubercle; abdomen with three rows of faint brownish spots 
dacdalus, new species, p. 32. 
3. Almost uniformly whitish species, the abdomen not marked with brown 
Oye (late ory ye a EE Daa ar SE eae ag 4 
Abdomen brown or gray, with pale spots or stripes, or gray, with dis- 
DLT CURR ONY IIE STOOLS ee See ee 5 
4. Frons of female less than twice as high as basal width; a short median 
Callus spLESeCMytes Se et Map yo ee ye niets oe magnicallus (Stone), p. 33. 
Frons of female over twice as high as basal width; no median callus 
OLESeTnipae ree Bee eee aes hes psammophilus (O. 8.), p. 34. 
5. Frons of female distinctly widened below; abdomen with three rows 
Oteray Spots (Hlorida ) Sts. 22) ee __floridensis (Hine), p. 34. 
Frons of female parallel sided or narrowed below; abdomen other- 
wiseauGwesternupart-of theeUnited. States). 22522) ee 6 
6. Abdomen with a median gray stripe and sublateral spots 
productus (Hine), p. 35. 
Abdomen light gray, with tergites 2-4 each with four brown spots 
cribellum (O. S.), p. 36. 
STENOTABANUS FLAVIDUS (Hine), new combination 
(Fig. 11, A) 
Tabanus flavidus Hine, Ohio Nat. 5: 236-237, 1904. 
Rather small; yellowish brown, with a conspicuous row of pale-yellowish- 
brown median triangles on abdomen; ocellar tubercle distinct; vein R: with 
an elongate stump. 
Female.—Length 11-14 mm. Hye bare or with very indistinct short pile, 
bluish green, with three diagonal purple bands. Frons gray, about five and 
