TRIASSIC INSECTS OF COLORADO. 405 



pound, the branches being scarcely more longitudinal than the mediastinal but increas- 

 ingly so as the apex is gained. 



The fragment, Nos. 24 and 64, is 13 mm. long and indicates a wing about 25-30 mm. 

 long, making it much the largest of the Fairplay cockroaches. The color is a uniform 

 dark brown. 



Petkablattina Scudder. 



This genus, established on forms discovered in carboniferous deposits, proves to be as 

 well developed in the triassic rocks as in the paleozoic series. 



Petrablattina aequa. 

 PI. 42, fig. 13. 



Petrahlattina aequa Scudd., Proc. Acad. Nat. Sc. Philad., 1885, 38. 



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, and beyond the basal cui've 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. 



Four specimens were obtained, one however showing nothing but the anal area, Nos. 

 20, 61, 62, 63. 



Petrablattina meieri. 

 PI. 42, fig. 17. 



Petraljlattina meieri Scudd., Proc. Acad. ISTat. Sc. Philad., 1885, 38. 



Mediastinal vein terminating a long way beyond the middle of the costal border, witli 

 comparatively distant, usually simple branches. Scapular vein terminating just below 

 the tip of the wing and beyond the basal curve, gently arcuate throughout, with bi-anches 

 similar to those of P. aequa, but occupying a larger area. In consequence, the externo- 

 median area is of less importance than in P. aequa, 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 interno- 

 median 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 

 Aving is broken at the base, but its probable length was 19 mm., and its l)i-eadth, 7mni. It 

 is named after Mr. Kobert A. Meier, of Garo, Col., in whose shaft all these specimens 

 were obtained, and who afforded our party all possible assistance in working them. 



A single sijecimen was secured, No. 25. 



MEMOIUS BOSTON SOC. NAT. HIST., VOL. IV. 62 



