

C|e dtanabiaii Entomologist. 



VOL. XIX. LONDON, SEPTEMBER, 1887. No. 9 



SOME NORTH AMERICAN TACHIN.^. 



BY BARON OSTEN SACKEN. 



[The following paper was left by Baron Osten Sacken [O. S. had left Washington 

 on Embassy about ten years earlier], with his collection of Diptera, in the charge of 

 Dr. H. A. Hagen, of the Museum of Comparative Zoology, Cambridge, Mass., by 

 whom it has been sent to us for publication. The description of the last species, 

 Tachiiia thcclanini, is by S. H. Scudder. — Ed. C. E.] 



Tachina (Exorista) futilis Say., MSS. ,^ , ? • Palpi, antennse and 

 legs black ; face, front and last abdominal segment with a brassy-yellow 

 reflection. Length, 7-10 m.m. 



Bottom of the antennal foveas silvery gray ; the lower part of the 

 cheeks likewise ; front, lateral parts of the face and the orbit of the eyes 

 below and behind (genal and occipital orbit) brassy-yellowish, the color- 

 ing of the front being of a more saturate yellow than the lateral parts of 

 the face ; above the antennas, in the middle of the front, a brown stripe, 

 attenuated posteriorly ; it bifurcates on the vertex, enclosing the grayish 

 ocellar triangle ; the hind plane of the head (occiput) gray. The row of 

 frontal bristles consists : ist, of three bristles pointing backwards, the 

 uppermost of which is placed on the top of the vertex ; 2nd, of three 

 shorter bristles pointing forward ; 3rd, of four or five bristles which form 

 diverging rows, descending on both sides of the antennae, the last being a 

 little below the end of the second antennal jomt. Between the frontal 

 bristles and the eyes, the front bears numerous little hairs ; between these 

 rows on the ocellar triangle is the usual pair of bristles pointing forwards. 

 The females have three supernumerary pairs of larger bristles ; the first is 

 placed behind the upper corner (yf the eye, the two others between the 

 frontal row and the orbit of the eye. Among the above described smaller 

 hairs, immediately below the last bristle, the brassy-yellow color of the 

 face shows a brown, changing spot, visible in an oblique light only; 

 below this place, the lateral parts of the face are smooth ; a short 

 distance above the oral margin there is, on each side, the usual long 

 bristle ; above it, some shorter hairs reach to about one-quarter of the 



