374 TERTIARY INSECTS OF NORTH AMERICA. 



vein, ami at the tip of tlie wing tlie}' curve away from eacli other; tlie two 

 cross-veins on tlie lower third of the wing are respectively slightly farther 

 from the base of tlie wing than tlie corresponding veins of the upper third ; 

 the fringe on the posterior border is largest near the tip of the wing, where 

 the hairs are about three times as long as those on the costal border. The 

 first hind tarsal joint is scarcely longer than broad, cylindrical ; the second 

 of about the same length but decidedly broader at apex than at base; 

 the apical joint is nearly globular, smallest at base, as large in the middle 

 as the base of the other joints. There are a few hairs at the tip of the abdo- 

 men and a few short ones on the hind tibias ; the apical ones stouter than 

 the others, resembling spines ; but the insect appears to have been unusually 

 destitute of hairs, excepting on the wings, where not only the edges but also 

 all the veins are fringed. 



Length of body, 1.6-1.8""° ; of antennae, 0.58""" ; of fore femora, 0.32""' ; 

 breadth of same, O.U™"'; length of fore tibia?, 0.32™" ; -of hind femora, 

 0.38"'™; breadth of same, 0.11"""; length of hind tibisE, 0.42"'™; of hind 

 tarsi, 0.12™"' ; of fore wings, 1.4™™ ; of hind wings, 1.27™™ ; greatest breadth 

 of fore wings, 0.37™™ ; length of prothorax, 0.16™™ ; breadth of same, 0.32™™; 

 length of whole thorax, 0.64""° ; of abdomen, 0.92™™ ; greatest breadth of 

 the same, 0.37™™. 



Fossil Caiion, White River, Utah. W. Denton. 



Family LYG^EID^E Westwood. 



This family has been recognized in the Secondary rocks by somewhat 

 obscure fragments in England and Germany, but in Tertiary deposits the 

 family is comparatively abundant and widespread. Curiously enough, only 

 two species have been recorded from amber, and in Menge's Collection the 

 family was represented by but one. Three-fourths of the known European 

 species are those described by Heer, who referred them to few genera. It 

 is difficult to place the larger number of those which have been recorded, 

 but to judge in part by the living species with which some of them are com- 

 pared it is plain that the M3'odochina should claim about one-half of them 

 and the Lygseina the larger part of the remainder, the others being distrib- 

 autble among the Cymina, Blissina, and Heterogastrina. In all there are 

 thirty-seven species credited to six genera. 



