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very numerous, which becomes very shorter up the back of the head 

 until it merges into the yellowish and brownish hairs on the vertex- 

 Frons diverging towards the antennae with tha straight sides,, the upper 

 end slightly narrower than one-fourth the width of the head., and the 

 lower end broader than the one-thirds the width of the head, flat but 

 1 1.1 idly flush with the eyes, covered with a whitish yellow tomentum ; 

 frontal callus black and shining, transversely oblong but with doubly and 

 slightly arched lower margin and with inconspicuously and inwardr 

 ly curved upper margin, large, moderately convex, and extending 

 almost from eye to eye but not quite to the antennae as in Chrysops 

 mlokosieiviczi, Bigot, longer and less convex than that of mlokosie- 

 ■zviczi ; ocellar triangle black and shining, almost trapezoidal, and nearly 

 flush with the eyes, the hind lateral angles reaching to the upper angle 

 of the eves ; antennal protuberance well divided by a very short median 

 sulcus into two lateral ones, slightly convex and yellow dusted but 

 with the margins of the cavities brownish. Pubescence on the frons 

 yellowish, very short and sparse, excepting of both the frontal callus 

 and antennal tubercle quite bare, on the ocellar triangle brown. Back 

 of the head entirely black and somewhat shining, leaving narrow yel- 

 lowish eye-margins, very slightly covered with a greyish tomentum, 

 bearing short yellowish hairs near the eye-margins, intermixed with a 

 brown pubescence at the upper part. Occiput black, very slightly 

 covered with a yellowish dust, and bearing short yellowish hairs above. 

 Proboscis slightly shorter than the depth of the head, rather slender, 

 blackish brown and slightly shining, bearing a very short blacki-h 

 pubescence which is much paler towards the base, and which is longer 

 but sparser beneath the sucker-flaps ; palpi a little longer than half the 

 length of the proboscis, yellow, slightly compressed and curved an- 

 teriorly and subpointed at the tip, bearing short whitish yellow pubes- 

 cence which becomes longer below the outer surface. Antennae very 

 slender, about three times as long as the length of the head ; first joint 

 a little longer than the second, but thinner and not dilated, yelIoAi T h 



