SCUDDEK ON TERTIARY INSECTS. 535 



It differs somewLat remarkably, however, from any of the genera given 

 in that author's Synoi)sis des Agrionines (1862) in several points, as will 

 be seen on reviewing the following characteristics. 



The median sector arises from the principal vein more than one-third 

 the distance from the nodus to thearculus; the subnodal arises from 

 an extension of the nodus, which in passing below the principal is 

 directed somewhat inicard instead of outward, a somewhat extraordi- 

 nary feature ; the nodal arises from the principal only as far beyond 

 the nodus as the median originates before it, or scarcely more than one- 

 fifth way to the pterostigma, which is four times as long as broad, sur- 

 mounts about four cellules, is a little dilated, oblique both within and 

 without, but especially pointed above on the outer side, touching the 

 costal margin throughout. The reticulation of the upper half of the 

 wing is mostly tetragonal, and in the discoidal area very open, while in 

 the lower half of the wing it is mostly pentagonal, and dense apically; 

 this results in part from the great number of interposed supplementary 

 sectors, of which there are several between the principal vein and the 

 ultranodal sector, and several between each of the following sectors as 

 far as the upper sector of the triangle; the upper of these curve some- 

 what downward as they approach the apical border. The postcostal 

 area has at first two rows of cellules, but it expands rapidly below the 

 nodus, and then has three and afterwards even four rows. The quadri- 

 lateral is only half as long again as broad, its upper somewhat shorter 

 than its lower side. The nodus is situated at an unusual distance out- 

 ward, indeed not very far he/ore the middle of the wing (about two-fifths 

 the distance from the base), and at a third of the distance from the 

 arculus to the pterostigma. The petiole terminates at some distance 

 before the arculus and is very slender. The wing is rather full in the 

 middle, and the apical half of the posterior border is very full, the apex 

 falling considerably above the middle of the wing. 



These characters show the nearest alliance to Philogenia, but the 

 genus differs strikingly from that in the position of the nodus, its 

 retreat below the principal sector, the character of the postcostal area, 

 and in the great number of the supplementary sectors, as well as in less 

 important characters, such as the density of the reticulation and the 

 form of the quadrilateral. It seems indeed to be a very aberrant mem- 

 ber of the legion. As the members of this group are all tropical, and 

 those to which this is most nearly allied (as indeed two-thirds of the 

 species) are from the New World, this is an additional instance of neo- 

 tropical alliances in the insect-fauna of our Tertiaries. 



It is upon the wing that I would establish this genus. Yet fragments 

 of other parts of the body occur with the wings, showing that the legs 

 were probably long and slender, furnished with spine-like hairs as long 

 as the breadth of the femora. The abdomen was moderately slender, 

 rather longer than the wings ; its ninth and tenth segments a little en- 

 larged, the tenth half as long as the ninth, and the eighth half as long 



