NOKPH AMERICAN DIPTKRA- 93 



27. — First basal cell longer tlian the second 28. 



First basal cell only as long as the second 29. 



28.~Lateral eniargination of the occiput distinct; head large. 



Ileterostyliiiii. 

 Lateral eiuargination of the occiput almost imperceptible; head small. 



BoiiibyliiiS!). 

 29. — Pile of face dense, concealing from view the face and base of antcnnie. 



Aiiastoei'liiis. 



Pile of face sparse, not concealing the face from view Ky.'»toecliU!<t. 



30. — Abdomen not narrowest at the base. 31. 



Abdomen narrowest at the base, slender, nearly naked $i.v$»ti'0|>iis. 



31. — Body clothed with more scales than hairs and curved semi-circnlarly. 



To.vopliora. 



Body more iiairy than scaly and nearly straight (iJ<'r«ii. 



32. — Scutellum deeply sulcate longitudinally Geiiiiiiaria n. gen. 



Scutellum convex, not sulcate LiOriloius. 



33. — First posterior cell closed far from the margin of the wing, last section of 



fourth vein curving forward before its apex 27. 



First posterior cell coarctate, or closed in or near the margin, last section of 



fourth vein straight Thlipsogaster. 



34.— Thorax of male furnished with small tubercles Tlieveiietiiiiyia. 



Thorax destitute of tubercles I^cliiliUiii. 



IIYPERALONIA Eond. 

 Hyperalonia gaywpliylax Loew. 



Described as an Exoprosopa. Through the kindness of Mr. Samuel 

 Henshaw, I have been put in posse.ssion of a drawing of the right 

 wing of the type specimen ; this shows, as I suspected, that several 

 errors occur in Loew's original description (Dipt. Am. Sept., Cent, 

 viii, No. 18). The apex of the marginal cell and the whole of the 

 first submarginal, excepting its base and apex, are grayish hyaline, 

 instead of being black, as stated in the description. 



ALDRIC HI.4 n. gen. 

 Antennje nearly twice as long as the head, first joint slender, 

 slightly shorter than the second, twice as long as broad, the second 

 tapering slightly to the tip; third joint slightly shorter but wider 

 than the second, greatly compressed, in outline nearly elliptical, but 

 the tip contracted into a short, cylindrical styliform process ; style 

 ajiicai, acuminate, one-third as long as the third joint. Face shorter 

 than diameter of first antennal joint. Proboscis projecting nearly 

 half its length beyond the epistoma, labelhe very large, nearly half 

 as long as the proboscis ; palpi nearly cylindrical, three-fourths as 

 long as the proboscis. Thorax each side bearing two ante-alar mac- 

 rochietse ; scutellum rounded behind. Abdomen nearly cylindrical. 



TKANS. AM. ENT. SOC. XXI. MAKCH, 1894. 



