OF THE TABANID^ OF THE UNITED STATES. 397 



Female. Yellow ; thoracic dorsum grayish, tip of the abdomen brown ; tip of antennae, 

 front tibite and tarsi black ; wings brown at the apex and with a brown stigma. Length, 

 9-10 mm. 



Palpi and antennsB ferruginous-yellowish ; the end of the third joint of the latter black- 

 ish or brown ; face grayish ; front comparatively narrow, yellowish above the antennae, 

 grayish aljove the callosity and yellowish-gray to\vard the vertex ; callosit}' nearly square, 

 blackish or black. Thorax yellowish ; the middle portion of the dorsum is grayish, which 

 color is tempered by a yellowish pollen ; pleurte and pectus, in part, gray. Abdomen ferru- 

 ginous-yellowish, clothed with a golden-yellow pubescence ; sixth segment brown on the 

 sides; seventh entirely brown; (in some s^^ecimens the preceding segments also show a 

 brownish tinge on the sides). Distal third of the front femora, the front tibice and tarsi 

 black ; distal half of the middle tarsi brownish ; hind tarsi, except the base, and hind tibiae, 

 more or less brown (the hind tibiae seem to vary in the intensity' of the coloring; in one 

 specimen they are brown, except at the base ; in another the brownish coloring is hardly 

 perceptible at all ; the third holds the middle between the two) ; the remaining portion of 

 the legs is yellow. Wings suljhyaline ; stigma brown ; the apex, inmiediately beyond the 

 tip of the second vein, is Iji'own ; this tinge becomes much fainter, however, toward the 

 hind margin ; a faint brown tinge in the proximal half of the first posterior cell enci'oaches 

 more or less on the first basal cell and extends along the central crossveins ; costal cell 

 yellowish. 



I have four female specimens before me ; two from Florida and two from Mexico. One 

 of the latter has the hind tibiae brown except at the base. 



This species occurs also in the Carolinas (Macquart), in the West Indies and Hondm-as 

 (C/irysops convcrgens Walker), and in Brazil (Macquart). 



The synonymy emijraces not less than six specific names ; Mr. Walker, in his List of the 

 Diptera of the British Museum, after having identified it once as Dichelacera ferrugata, 

 describes it twice as a new species, and quotes it a fourth time as Diabasis atcenia. The 

 descriptions of Clirysops convergens Walker, and ajjj^roximaiis Walker, which are beside 

 each other, are absolutely identical ; a slight difliirence appears in the hind legs, the coloring 

 of which, as I have sho\vn, is variable. The other synonymies wUl not seem in the least 

 doubtful to any one who will take the trouble to compare them. 



MEMOIRS BOST. SOC. KAT. HIST. VOL. U. 100 



