1885.] NATURAL SCIENCES OF PHILADELPHIA. 113 



ELISAMA 



figured by Broclie certainly belong together, and seem to consti- 

 tute a natural genus. By the kindness of Rev. Mr. Broclie, I 

 have seen the original of his pi. v, fig. 1 (Elisama Kneri of 

 Giebel) and another specimen which seems to belong to E. 

 minor, so that I can more fully characterize this genus. The 

 mediastinal and scapular veins appear here to constitute one 

 vein, and to occupy almost the entire upper half of the wing. 

 The externomedian and internomedian veins fill the lower half 

 between them with parallel veins, which at their origin curve at 

 once strongl}' downward, and then run longitudinally to the 

 apical margin, leaving only the meagrest possible space to the 

 anal area, which is indeed broken off from the two specimens I 

 have seen, and does not appear in the figures published by 

 Brodie. In addition, in both the species, there is an abundant, 

 but imperfect, cross-venation at the base of the externomedian 

 and internomedian areas, and on the latter a large discolored 

 spot, which may of course be confined to these two species only. 



RITHMA 



contains more incongruous material. I have myself recognized 

 in the English species I have examined autoptically only one of 

 the species referred to it, named R. Murchisoni \>y Giebel, and 

 this is certainly to be referred to Mesoblattina Geiriitz. R. rami- 

 ficata is cpiite too imperfect to be considered until better 

 specimens occur. It is probable that R. antiqua should be 

 separated from the others, and the same may be true of R. 

 Westivoodi. This leaves two species, R. purbeccensis and R. 

 Morrisi, which agree well together, and represent a group which 

 seems to have flourished in mesozoic times, as I have seen a 

 number of species from the English Lias belonging with them, and 

 Blattina formosa Heer from Schambelen, and Blattina Hasina 

 Gieb., figured by Brodie, also belong here. These wings are 

 rounded wedge-shaped, with the amalgamated mediastinal and 

 scapular area so large as to occupy about half of the wing, 

 the vein running in a slightly sinuous course to, or even below, 

 the tip. The anal area is generally pretty large, convex, and filled 

 with parallel veins, which terminate on the margin. The space 

 between is divided about equally between the externomedian and 

 internomedian veins, which generally take a somewhat sinuous 



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