354 JR. H. Sellards — Types of Permian Insects. 



of uniting at the base. This is doubtless due to crushing by 

 which the radius is pushed partly over the subcosta. The 

 subcosta is restored in the drawing as seen in other genera of 

 the family. 



Length of abdomen, 16 mm . Length of wing, 17 ram ; width, 

 4 l/2 mm . 



Therates planus gen. et sp. n. 



An aberrant genus probably indicating a subfamily of the 

 Protereismephemeridse is represented by two specimens, one 

 showing the basal three-fourths, the other the basal one-half 

 of the wing. The wings are slender, thin and but feebly cor- 



FiG. 13. Doter minor gen. et sp. n. Body, caudal setse, and one pair of 

 wings preserved. The inner half of the right wing is folded across the outer 

 half. In the left wing a small part only of the inner border, including the 

 anal area and a small part of the cubital area, is folded across the rest of the 

 wing. The wings are shown beneath in the figure as they would appear 

 with the folds straightened out. In the counterpart of the specimen the seg- 

 ments of the abdomen are somewhat more distinctly seen. The segments 

 are short, being somewhat wider than long. The dotted vein in the right 

 wing connecting the radial sector with the media is not observed in the 

 specimen, being either lacking or obscured by the folded wing. It is restored 

 as seen in the left wing. Enlarged 5 times. 



rugated. The costal brace is strong and reaches 3 to 3 l/2 mm 

 from the base. The costal border is straight; the inner border 

 is gradually rounded to the slender basal attachment. The 

 media is strong and fuses with the radius back of the costal 

 brace, not in front of the brace as in other genera described. 

 The cubitus approaches very 'close to the radius, lying either 



