68 Journal New York Entomological Society, f^'o'- xxv. 



ing a number of specimens with the types in the Museum of Com- 

 parative Zoology at Cambridge, and for many suggestions in sep- 

 arating the different species. Mr. J. M. Aldrich kindly sent me 

 notes on the specimens of this group in his collection. There are 

 several specimens in the National Museum which I left unnamed, their 

 position being at present uncertain, on account of the lack of ma- 

 terial. 



Osten Sacken was I believe the first to call attention to the re- 

 lated forms of Anthrax grouped around A. halcyon Say, the first in- 

 stance being in Western Diptera, p. 239. In the Biologia (Diptera, 

 Vol. i) he defines this group and refers the following species to it: 

 halcyon, arethusa, alpha, poccilogastcr, ceyx, flaviceps, and fuUginosa. 

 Osten Sacken gives the following distinguishing characters for these 

 species: "the Exoprosopa-like front legs (short; tibiae without 

 spinules; tarsi very gently tapering, with rather indistinctly marked 

 joints, and a delicate pubescence of erect hairs on both sides; ungues 

 very small) ; the face conically produced, the proboscis not project- 

 ing beyond the oral margin; the third joint of the antennse in the 

 shape of an irregular cone, gradually tapering off into a long point 

 (but not a style). The coloring of the wings characteristic, brown, 

 with a clear space at the apex, traversed by the more or less clouded 

 ' S '-shaped anterior branch of the third vein; a clear space in the 

 discal cell, more or less connected with the posterior margin ; super- 

 numerary cross-veins often occur, bisecting either the third posterior 

 or the second submarginal cell ; a stump of a vein in the third pos- 

 terior cell is very often present. Another peculiarity of this group 

 is that the impressed line which, in most species of Anthrax, issues 

 from the emargination of the occipital orbit, and crosses a portion 

 of the eye, is very short and almost obsolete here." 



Osten Sacken gives this group the name " Poecilanthrax." As to 

 structural characters, there is practically no variation, although size 

 may prove a good character. The coloring and pattern of the wings 

 varies in specimens of the same species, but the general design is con-, 

 stant and characteristic of the species. The small stumps of veins 

 occurring quite often are variable, as are supernumerary cross-veins. 

 Very little can be added .to Osten Sacken's characterization of '' Poecil- 

 anthrax." The species are all comparatively large and all the species 

 known have black pile on the sides of the abdomen, usually in tufts 



