BLATTOIDEA. 93 



and apex of the wing are missing, or still concealed in the matrix. Few definite 

 factors are presented for determination, and the following description is the 

 best we can give. 



The outer margin of the wing is formed by the cost a, and seems to be 

 curved basally and straight distally. The costal area is widest at the base, 

 and gradually narrows by the approach of the subcosta, which doubtless reached 

 the outer margin far out, The costal area is crossed by a few stout straight 

 branches of the subcosta. The subcosta passes straight from the base to the 

 distal portion of the wing-margin. 



The radius is close to and parallel with the subcosta. It gives off two 

 inward diverging branches, the first uniting with the median, but giving off a 

 secondary branch before it reaches the latter. The median gradually diverges 

 from the radius. It gives off two well-marked inner branches, and then bends 

 forwards to join the first branch of the radius. The point of union of the two 

 branches gives origin to a backward twig parallel with the secondary branch 

 of the radius, and with the two inner branches of the median. 



The cubitus is represented by a long oblique vein going down to the inner 

 margin. It gives off near its base an outer branch, which curves inwards 

 parallel with the main stem, and reaches the wing-margin much beyond it. 

 The wing appears to have broken along the level of a succeeding vein, but 

 whether this was also a cubital or an anal vein it is impossible to determine. 



The interstitial neuration consists of a series of stout strong cross-nervures. 

 The texture of the wing seems to have been membranous. 



Affi irities.— The chief features of the wing are the strong parallelism of the 

 veins, the numerous and strong cross-nervures, and the unusual mode of union 

 of the radius and median. This assemblage of characters serves to place the 

 specimen in the Protorthoptera, but it is not referable to any known genus, and 

 is too incomplete to justify a new genus for its reception. The nearest approach 

 appears to be Progenentomum carbonis, Handl., in which the subcosta reaches 

 the middle of the wing, the radial sector unites with the median, and the interstitial 

 neuration is of straight cross-nervures. 



Order BLATTOIDEA. 



The most numerous and varied insects found in the Coal Measures are the 

 Blattoids, the recorded forms being classified in several families, embracing nearly 

 100 genera and 400 species. The early history of their study is dealt with by 

 S. H. Scudder ('Mem. Bost. Soc. Nat, Hist.,' vol. iii, pt. 1, no. 3, 187 ( J), and need 

 not be repeated here. 



Notwithstanding the abundance of specimens and forms known, they are 

 insufficient for a satisfactory classification of the group, and do not provide the 



