AMERICAN DIPTERA. 223 



Specimens have been examined from Mass., Mich., 111., Wise, 

 La., Neb., Kans., So. Dak., Colo., Wyo'ni., Idaho, N. Mex., Calif., 

 Mexico. 



Among these specimens, which doubtless are of a single form, the 

 variations are extreme. Sometimes the tarsi are pure yellow, more 

 often sharply annulate, though at times they are dusky. A few of 

 the specimens from Wyoming have almost black feet. The legs 

 vary from reddish brown to almost white. At times the two basal 

 cells of the wings are equal, more often the second is the longer. 

 The sixth vein is more or less abbreviated at the base. The face 

 varies from white to red or fuscous, and varies also greatly in 

 breadth. The last antennal joint is generally lanceolate, but fre- 

 quently is short. 



Flat.ypal|>ii!$ crassifemoriK Fitch. 

 Oscinis crassifemoris Fitch, N. Y. Reports, vol. i (1856), p. 301. 

 Platypalpns debilis Loew, Cent, iii, 37 (1861). 



Although Fitch's description of Oscinis crassifemoris is very 

 meagre, Mr. Coquillett who had the type for examination places it 

 with Platijj)alpus debilis Loew. 



The description of crassifemoris is given in full : 



"The thick-legsefl Oscinis [0. crassifemoris) is the same size with the last (0. 

 coxendix. which is 0.07 inch in length to the tip of the abdomen, and 0.10 to the 

 end of the wings), and is black, with a white head, and the thorax with a gray 

 reflection. The last joint of the antennae with its bristle is black. The legs are 

 pale yellow, the tips of the feet black. The veiulets are so near each other that 

 they are almost united. In the female the abdomen is egg shaped and polished, 

 its apex drawn out into a long, sharp-pointed ovipositor. The middle and ante- 

 rior thighs are rather short and thick, the hind ones longer and cylindrical. 



The specimens referred to this species are variable in tarsal color- 

 ing, sometimes the tarsi are yellowish, with dusky tips and some- 

 times annulate. The antennae are sometimes black, in which case 

 this species may readily be distinguished from cequalis and hastahis 

 by the smaller tibial spur and the shape of the third antennal joint. 



Massachusetts (Hough), Michigan, Idaho (Aldrich). 



Platypalpiis tenelliis sp. nov. (Figs. 28, 38). 

 Length 2-2.5 mm., length of wing same. — Black, head, dorsum of thorax and 

 pleurje covered with gray pollen, abdomen shining. Face silvery, rather nar- 

 row, sides of front parallel. Autennse yellow-red; third form cordiform, 

 pointed, sometimes blackish ; arista longer than antenna. Palpi and proboscis 

 yellowish, the latter one-half of the head height. Thoracic bristles yellow, 



TRANS. AM. ENT. SOC, XXVIII. JULY. 1902. 



