Vicinity of Mason Creek, Illinois. 



299 



Fig. 



Fig. 2. Athymodictya parva 

 (negative of left wing), x 2 - 5. 



longest of all, being somewhat broader than long. All the 

 seven segments preserved are provided with narrow lateral 

 lobes. 



Wings' with very broad base, horizontally expanded. 

 Anterior and posterior wings similar, the latter with distinctly 

 dilated basal half. Costal area very narrow'; subcostal vein 

 and radius very close together. Radial sector farther removed 

 from the base in the anterior 

 than in the posterior wing, sep- 

 arated by a rather broad space 

 from the radius and probably pro- 

 vided with a single branch, cleft 

 into about 3 twigs. Medial vein 

 split somewhat before the origin 

 of the radial sector into a forked 

 anterior branch and a posterior 

 branch divided into 3 twigs. 

 Anterior branch of the cubitus 

 rising very near the base, simple 

 in the anterior wing and forked 

 in the posterior ; posterior branch 

 of the cubitus split into a simple and a forked twig. Three 

 to four short anal veins. All the spaces between the veins 

 filled with a delicate irregular network, one of the character- 

 istics of the Dictyoneuridse. 



Holotype in Peabody Museum, Yale University, Cat. No. 18. 



Family SYNTONOPTEEIDiE, new family. 



A splendid anterior wing of a more highly specialized 

 Palseodictyopteron induces me to establish a new family, which 

 may be placed near the Mecynopteridse and Lithomantidae. 

 The most striking characteristics of the new family are the 

 division of the wing into four nearly equivalent triangular areas, 

 occupied by the sector, the two halves of the media, and the 

 cubitus ; the S-shaped origin of most of the twigs ; and the 

 comparatively long-vaulted anal veins, provided with a rather 

 great number of short branches. 



Syntonopteea, new genus. 



Syntonoptera schucherti, new species. Fig. 3. 



Negative of a left anterior wing with broad base. Length 

 about 90 mm , of which 80 mm is preserved. Costal area broad 

 near the base, with pointed apex. Costal and subcostal vein 

 convergent ; radius nearly parallel with the subcosta and 

 moderately far removed. Radial sector rising at about one- 

 quarter of the length of the wing, separated from the radius 



