302 TERTIARY INSECTS OF NORTH AMERICA. 



Family JASSIDES Amyot-Serville. 



With only a single exception all the fossil species of this family that 

 have been recognized in Tertiary deposits of any kind have been drawn 

 from the subfamily Jassida as Stal separates them. This is equally true 

 when we extend the ground to America, which possesses half as many 

 species as Europe, and is the more remarkable since the Membracida, now 

 such a prevailing type in North America, is nowhere traced in the rocks, 

 though in Europe a single Oeningen species, imperfectly preserved, has 

 been referred here by Heer. So, too, the vast proportion of forms in both 

 worlds belongs to the series allied to Jassus and Bythoscopus, and not to 

 that of which Tettigonia is the type, so that the resemblance of the Tertiary 

 fauna in the two worlds is not slight, though the same genera appear rarely 

 to be preserved. 



TETTIGONIA Fabricius. 



Tin's genus, excessively abundant in existing species, especially in the 

 tropics of the New World, has not been recognized in the Tertiaries of 

 Europe. A single species from White River, Colorado, has been referred 

 here, but its generic affinities are wholly uncertain. Not so, however, with 

 the ones now added from Green River, Wyoming, and Florissant, Colorado, 

 which are unmistakable members of the genus, at least in the broad sense 

 in which Signoret employed it. Their presence in Florissant and Wyoming 

 is in keeping with the tropical or subtropical aspect of the Tertiary insect 

 fauna of these places. 



Table of the species of Ttitigonia. 



Larger species; tegmina ornamented with a broad dark band around the apical margin but with no 



cross bauds \. T. priscomarginata. 



Smaller species ; tegmina with no broad anical marginal baud but with distinct cross bands. 



I!as:il half'of tegmina with a broad, dark, median streak its entire length 2. T. priscotincla.. 



Median streak of tegmina not extending beyond the basal fourth 3. T. priscovariegata. 



.*, The fourth species, from its imperlection, is not here noted. 



1. TETTIGONIA PRISCOMARGINATA. 

 Pi. 7, Fig. 4. 



A single specimen and its reverse with partially expanded tegmina. 

 A species is indicated of about tile size of our Aulacipes irroratus Fabr. sp., 

 and with a head of probably the same form. The head is scarcely shorter 

 than the transverse thorax, and the tegmina are fully three times as long as 



