274 E. T. CRESSON, JR. 



and the series of short minute appressed thorn-like bristles 

 on the tibiae, which are more distinct when the latter are 

 yellow ; the tarsi have long fine hairs at the apices of the 

 joints. Claws generally very long and curved at tips, with 

 large spatulate pulvilli and hair-like empodium. Wings 

 hyaline, or, evenly gray or brownish, not maculate ; vena- 

 tion varying as shown in the figures under the various 

 species. 



TABLE OF GENERA. 



1. Discal cell incomplete, the fourth vein beyond the anterior cross-vein 



being rudimentary and the posterior cross-vein wanting. 



Chalarus. 

 Discal cell complete 2. 



2. Head nearly spherical; occiput with turgid margin, being gener- 



ally widely visible behind the eyes ; ocellar bristles absent..3. 



Head truly hemispherical ; occiput not widely visible, i. e., the head 



being closely applied to the thorax ; ocellar and scutellar 



bristles distinct; pilose species Vevrallia. 



3. Scutellar bristles well developed; third antennal joint reniform. 



Neplirocerns. 



Scutellum and mesonotum without distinct bristles ; third antennal 



joint acute or acuminate Pipmiculus. 



CHALARUS Walker. 



This genus is at once distinguished by its venation. Only 

 one, the European, species is known here,. Aldrich, in his 

 catalogue, mentions that we have an undescribed species ; 

 and there is also another recorded from the White Mountains, 

 New Hampshire, by Coquillett (1896 Slosson 263). 



C. spurius Fallen (Figs. 1, 43, 152), has been reported from 

 New Hampshire (1902 Slosson 7), and from New Jersey 

 (1899 Smith 666), and before me are a number of specimens 

 from Norwich, Vt.. Mt. Ascutney, Vt., Rockport, Mass., 

 Auburndale, Mass. {Johnson, B. S. N. H.); and Swarth- 

 more, Pa. (Cresson, A. N. S.). Taken June to August. 



VERRALLIA Mik. 



Allied to Pipunmhis, but more distinctly pilose, with a 

 pair of prominent ocellar bristles ; the head is closely ap- 

 plied to the thorax, so that the occiput is not puffed out 

 behind the eyes as it is in that genus ; the third antennal 



