1885.] NATURAL SCIENCES OF PHILADELPHIA. Ill 



side of the middle of the wing. The anal area extends nearly to 

 the middle of the wing, where it is marked by a considerable 

 emargination, and its veins are frequent, oblique, mostly simple, 

 and terminate on the margin. Length of wing, 7 mm.; breadth, 

 3 mm. 



Triassic beds near Fairplay, Colorado. Named after Mr. Chas. 

 Brongniart, of Paris, well known for his remarkable discoveries 

 among the older fossil insects. 



Scutinoblattina intermedia, sp. nov. 



This species resembles the last, but is not marked by any dots, 

 and the anal area, while shorter, shows no emargination of the 

 border at its extremity ; the anal veins are very close, parallel to 

 the inner margin, and terminate not on the margin, but on the 

 anal furrow. It further differs in that the externomedian branches 

 are considerably more longitudinal than those terminating on the 

 costal margin. Length of wing, 7 mm.; breadth, 2*75 mm. 



Triassic beds near Fairplay, Colorado. 



Scutinoblattina recta, sp. nor. 



This species, the smallest and most abundant of all in the 

 Triassic rocks, is rather slenderer than the others, and has the 

 surface finely reticulated. The mediastino-scapular and externo- 

 median veins run side by side in perfectly straight lines from the 

 middle of the base to the middle of the tip, the branches, very 

 few in number, parting similarly on the two sides. The costal 

 is more arched than the inner margin, and where they can be 

 made out, the one or two anal veins seem to run to the margin, 

 but all the veins on the wing are exceedingly obscure. Length 

 of wing, 6*3 mm.; breadth, 2*4 mm. 



Triassic beds near Fairplay, Colorado. 



III. On the Genera hitherto proposed for Mesozoic Blattarise. 



Brodie, in 1845, published figures of a considerable number of 

 mesozoic cockroaches, but named only one, which he referred to 

 the genus Blatta. In 1852 Heer figured and named another under 

 the equally broad generic name Blattina. Westwood, in publish- 

 ing in 1854 a considerable addition to our knowledge of the cock- 

 roaches of the English mesozoic rocks, separated four somewhat 

 peculiar forms under the generic term Blattidium ; the rest were 



