160 E. II. Sellards — Types of Permian Insects. 



thin and indistinct. The subcosta is arched at the base toward 

 the costa and reaches to the middle of the wing. The radius 

 reaches to the apex. The sector is simple. The media divides 

 just in front of the origin of the sector, both divisions remain- 

 ing simple. Cubitus is a very long vein reaching well along 

 the apical border. It is thin and indistinct and gives off six 

 slender branches. 



The hind wing is broader than the front, and is not more than 

 three times as long as broad. The sector arises very early. 

 The basal part of the cubitus is a heavy, strongly impressed 

 vein, directed toward the inner border. From near the middle 

 of the cubitus a thin forwardly directed branched division is 

 given off which reaches to the apical border. The greater 

 width of the hind wing results from the expansion of the inner 

 border, and the greater area occupied by the cubitus. The 

 anal area is unknown. The deeply impressed character of the 

 cubitus leads one to expect a folded anal area. The membrane 

 of the hind wing is of coriaceous wrinkled appearance similar 

 to that of the front wings. 



Length of front wing about 13 mm ; width, 3 mm ; length of 

 hind wing about 12 or 12i ram ; width, 4 mm . Type, No. 143. 



Prohiis coriacea sp. d. 



The cubitus in this species is scarcely so distinctly vaulted 

 as in the case of the type species of the genus. Media divides 

 opposite, rather than in front of, the origin of the sector. 



Length of front whig, 12 ram ; width, 3i mm . Type, No. 655. 



Espira obscura gen. et sp. n. Text figure 13. 



This genus is characterized by the very early origin of the 

 sector ; by a three or four branched media ; and by a cubitus 

 more vaulted and occupying a broader area, resulting in a pro- 

 portionately broader wing than in the type genus. Espira resem- 

 bles Prohiis in the late origin of the first cubital branch. It 

 represents a type with broader and stronger wings, and with 

 thickened membrane in which the veins can scarcely be traced. 



Length of wing about ll| mm ; width, 3-| mm . Type, No. 101. 



Stoichus elegans gen. et sp. n. Text figure 12. 



Media divides opposite the origin of the sector and is four 

 branched. Cubitus is short and has beyond the first strong 

 division but three branches. Cu x is vaulted at its separation 

 from Cu 2 and is connected to the media by a strong cross vein. 

 Cu 2 is much stronger than in the genera of this family already 

 described. 



Length of front wing, ll ,nm ; width, 3f mm . Type, No. 974. 



