1928] Table of North American Species of Medeterus 
43 
51 Knobs of halteres infuscated, at least on one side, (New 
Jersey) modestus Van Duzee. 
Knobs of halteres yellow 52 
52 Last section of fifth vein only half as long as the cross-vein, 
(California) xerophilus Wheeler. . 
Last section of fifth vein a little longer than the cross-vein, 
(specimens in which the thoracic vittse are obsolete), 
(North America) veles Loew. 
Last section of fifth vein twice as long as the cross-vein, 
(New York; New Jersey: Alaska). . . distindus Van Duzee 
53 Posterior cross- vein with a stump vein near its center, (Cali- 
fornia) . xerophilus Wheeler. . 
Cross-vein normal, without a stump vein 54 
54 Posterior basitarsus narrowed at base below and with a 
small tooth on this narrowed portion 55 
Posterior basitarsus without a tooth below, not narrowed at 
base 56 
55 Small species, 2 mm.; third and fourth veins rather far 
apart at their tips for the genus, (North America) 
veles Loew. 
Larger species; 3 mm. or over; third and fourth veins with 
their tips close together as usual in the genus, (California) . 
calif or niensis Wheeler. 
56 Last section of fifth vein only half as long as the cross-vein, 
(California) xerophilus Wheeler. . 
Last section of fifth vein longer than the cross- vein, or 
equal to it in length 57 
57 Last section of fifth vein and the cross-vein of nearly equal 
length; knobs of halteres more or less infuscated, New 
Jersey) modestus Van Duzee... 
Last section of fifth vein much longer than the cross- vein . 58 
58 Length of last section of fifth vein to cross-vein as 14 to 10, 
(Texas) albisetosa Van Duzee, new species.... 
Last section of fifth vein twice as long as the cross-vein ? 
(New York; New Jersey; Alaska). .. distindus Van Duze 
