38 PROCEEDINGS OF THE ACADEMY OF [1885. 



Petrablattina eequa, nov. *)>. 



Mediastinal. vein terminating scarcely beyond the middle of 

 the costal margin, with numerous, closely crowded, simple 

 branches; scapular vein terminating above the tip of the wing, 

 ami beyond the basal curve nearly straight, with four or five 

 singly forking branches ; branches of externomedian vein straight, 

 superior, mostly simple, parallel to the main scapular vein ; the 

 internomedian area extending to some distance beyond the 

 middle of the wing. It is a tolerably large species, the wing 

 measuring 24 mm. in length and 10 mm. in breadth. 



Triassic beds near Fairplay, Colorado. 



Petrablattina Meieri, now sj>. 



Mediastinal vein terminating a long way beyond the middle of 

 the costal border, with comparatively distant, usually simple 

 branches. Scapular vein terminating just below the tip of the 

 wing and beyond the basal curve, gently arcuate throughout, 

 with branches similar to those of P. aequa, but occup3*ing a 

 larger area. In consequence, the externomedian area is of less 

 importance than in P. sequa, and it has but few branches, which 

 appear to be generally simple, and slightly declivent, though 

 superior. Unfortunately this portion of the wing in the single 

 specimen known is very obscure. The internomedian vein is 

 not preserved in its outer portion, but it evidently reached the 

 border nearer the base than the mediastinal vein, and the anal 

 furrow is strongly curved. The wing is broken at the base, but 

 its probable length was 19 mm., and its breadth 7 mm. It is 

 named after Mr. Robert A. Meier, of Garo, Col., in whose shaft 

 all these specimens were obtained, and who afforded our party 

 all possible assistance in working them. 



Triassic beds near Fairplay, Colorado. 



POROBLATTINA {ndpos, Blattina), nov. gen. 

 Allied to Petrablattina, and especially the species of that genus 

 found in the same Triassic rocks, differing from them principally 

 in the insignificant part played by the mediastinal area and the 

 corresponding importance of the scapular area. The mediastinal 

 vein extends no further out than the anal, terminating far before 

 the middle of the wing, and has consequently but a few offshoots; 

 while the mediastinal, sweeping downward, away from the costal 

 margin at the termination of the mediastinal, occupies nearly half 



