HEMIPTEEA— HOMOPTERA— CERGOPID^. 3 1 9 



forks, when, after reaching their widest, the two forks run exactly parallel 

 to the costal margin, fading in the darker outer third of the wing; the 

 bi-anches of the ulnar vein originate as in the last species, and are parallel 

 to the radial branches, all being also equidistant. 



Length of tegniina, 9'""'. 



Green River, Wyoming. One specimen, Nos. 1 1 and 125, Dr. A. S. 

 Packard. 



3. Cercopis suffocata. 



PL 19, Figs. 2, 3. 



A single one of the tegmina of an insect with the clavus gone, but very 

 different in its markings from anything known. Its simple neuration allies 

 it directly with the other species referred here ; the radial, however, is dis- 

 tant throughout from the margin. The costal margin is very regularly and 

 considerabh* convex, and the apex very strongly rounded, produced, and 

 almost pointed. A broad and uniform belt of dark color follows the costal 

 mai-gin at the base for nearly two-fifths its course, in striking contrast to 

 the generally pale color of the wing, and distally joins a similar transverse 

 and slightly oblique bar crossing the wing as far as the sutura clavi ; all the 

 base of the wing, dark or light, is finely and distantly punctuate, as shown 

 in Fig. 2 ; a second transverse and similarly oblique dark band, slightly 

 broader, crosses the wing just before the apex, its inner border just striking 

 the tip of the sutura clavi. 



Length of tegmina, 8.5""" ; breadth at tip of sutura clavi, 3°"°. 



Florissant. One specimen, No. 262. 



PETROLYSTRA Scudder (Trsrpo?, Lystra, nom. gen.). 



Petrolysliu Scudd., Bull. U. S. Geol. Geogr. Surv. Terr., IV, 530-531 (1878). 



One of the most striking instances of tropical affinities in the Tertiary 

 shales of Florissant is found in the presence of two species of a genus of 

 huge Homoptera, rivaling the famous lantern-fly of South America in size, 

 but diff'ering in neuration and other features from any genus hitherto de- 

 scribed. At first glance one would think that it belonged to the Fulgorida, 

 a subfamily which, with Stridulantia, includes most of the larger forms of 

 the suborder, and to be somewhat nearly allied to Paralystra; but it differs 

 from this, and, so far as I can determine, from all Fulgorina, in the minute- 



