430 C. R. OSTEN SACKEN'S PRODROME 



46. -{ 



50 



'Crossveins and bifiirention of third vein with distinct brown clouds; lateral whitish spots on abdomi- 

 nal segments distinct 47. lasiophthalmus Macq. 



Crossveins and bifurcation of third vein not clouded ; lateral whitish or yellowish spots on abdominal 



I segments indistinct 47. 



._ J 17-20 mm. long. Second joint of palpi narrow 48. affinis Kirby. 



' 1^ 15-16 mm. long. Second joint of jjalpi stout at base 49. SOCius n. sp. 



jTlie lateral whitish spots on abdomen do not Moueh the hind margins of segments 49. 



I^The lateral whitish spots on abdomen rest with their broad base on the hind margins of segments . 50. 

 fThird antennal joint rather narrow, and hardly excised at all ; crossveins and bifurcation of third vein 



49 J without any clouds 50. septemtrionalis Loew^ 



I Thinl antennal joint moderately broad and distinctly excised; crossveins and bifurcation of third vein 



[ with faint brown clouds 51. illotus n. sp. 



I Second joint of paljii stout at base 51. 



1 Second joint of palpi narrow and rather long 53. astutUS n. sp. 



"Bifurcation of third vein without any vestige of a cloud; third antennal joint remarkably narrow, not 



excised ; subcallus not denuded (eastern species) 52. microcephalus n. sp. 



51. A Bifurcation of third vein with a foint vestige of a brown cloud ; third antennal joint, although narrow, 

 still with a distinctly projecting upper angle ; subcallus denuded, black, shining (western species) 



54. rhombicus n. sp. 



DESCRIPTION OF THE SPECIES. 



A. Tabani with glabrous eyes, and without ocellar tubercle. 



1. Tabanus turbidus. 



Tabanus turbidus Wiedemann, Auss. Zw., I, p. 124, 20. 



Female. Palpi reddish, with minute black hairs; face yellowish gray, antennas fer- 

 ruginous ; upper angle of the third joint sharp, projecting, but not drawn out in a point ; 

 annulate portion of the third joint rather long, but little shorter than the body of the joint, 

 the single joints composing it very well marked ; front yellowish gray, distinctly narrowed 

 anteriorly, darker brown in the middle ; frontal callus brownish red, fully twice as long as 

 it is broad ; above it a smooth stripe of the same color (sometimes bifurcate at its upper 

 end). Thorax with a grayisli ^JoUen, forming more or less distinct longitudinal stripes ; 

 the reddish brown or brownish red ground color is distinctly visible between them ; scutel- 

 lum concolorous with the thorax, and also covered with a grayish pollen ; pleurae uniformly 

 didl whitish yellow. Abdomen brownish, with a white spot in the middle of the first seg- 

 ment and with large triangular spots of the same color on segments 2-6 ; these spots do 

 not differ much in size, that on the sixth segment alone being smaller ; the whitish borders 

 on the hind margins of the segments are rather narrow, but expand laterally. Venter 

 bro^vnish red, with whitish incisures. Legs brownish red, hind tibiae with a but little con- 

 spicuous fringe of black hair. All wing veins (longitudinal as well as crossveins) are 

 broadly margined on both sides with brown clouds, the interior of the cells remaining sub- 

 hyaline ; posterior margin of the wings also faintly margined with brown ; first posterior 

 cell broadly open. Length, 20-22 mm. 



Ilab. Georgia (J. Eidings) ; Kentucky (Wied.). Four females. "Will be easily recog- 

 nized by the ]oeculiar coloring of its wuigs, the very long and comparatively narrow red- 



1 See the foot-note on page 427; in T. illotus the -whitisli reaching the hind margin, as the white pubescence, covering 

 spots on the second segment often have the appearance of them in well preserved specimens, extends to that margin. 



