80U0DER.] CANADIAN FOSSIL INSECTS. 7 



Gbrancon Soudder. 

 Gerancon Scudd., Tert. Ins. N. A., 248 (1890). 



Wings only known. Fore wing with the stigmatic vein arising from 

 the middle of the stigma. Cubital vein twice forked, the first time 

 very far from its origin, which is near the middle of the proximal 

 half of the space between the base of the first oblique and the stigmatic 

 veins, the second time scarcely behind the base of the stigmatic vein. 

 Second oblique vein arising many times nearer the first oblique than 

 the cubital vein and close to the former, the first discoidal cell between 

 them about ten times broader on the hind margin than at the base. 



Two species of this genus are known, one from Florissant, Colorado, 

 the other that described below. 



Gerancon petrorum. 



Lachnus petrorum Scudd., Rep. Progr. Geol. Surv. Can., ISYS-^B, 



279 (1878). 

 Gerancon petrorum Scudd., Tert. Ins. N. A., 249-250, pi. ii. 



fig. 6 (1890). 



A fragment of a wing is sufiiciently preserved to show that it should 

 be referred here. The wing is unusually slender ; the postcostal vein 

 thickens apically as it merges in the stigma ; the first oblique vein is 

 straight ; the second originates very close to the first, runs parallel to 

 it only at the very base, and then bends pretty strongly outward, strik- 

 ing the margin of the wing nearly as far from the tip of the first 

 oblique vein as half its own length ; the origin of the cubital vein is 

 not clear, but it is apparently not far out, in which caise it runs parallel 

 with the second oblique vein until it branches in the middle of the 

 wing ; the lower of these branches almost retains the course of the 

 basal part of the veins, but diverges slightly from the second oblique 

 vein, terminating very far from it on the border of the wing ; the 

 main stem, diverging from the first branch rather widely at first, 

 almost at once runs parallel to the lower branch, and when it has 

 continued a less distance than the main vein before its furcation, 

 divides, the two forks diverging but slightly at base, and then very 

 gradually converging until they are no farther apart than the bases of 

 the first and second oblique veins, and the upper fork almost touches 

 the stigmatic vein (probably by some displacement) ; together they 

 diverge a little from the lower branch of the cubital vein ; the stigmatic 

 vein is very conspicuous, passing by a broad sweep into the heart of 



