MirKOl'TKlIA ODONATA A<;i;iOM\A. 129 



It differs somewhat remarkably, however, from any of the genera given in 

 that author's Svnopsis des Agrionines (1SIL*) 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 troin the nodus to the arculus ; the subnodal arises from an 

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

 somewhat imrnri! instead of outward, a somewhat extraordinary feature ; 

 the nodal arises from the principal only as far 'nevond the nodus as the me- 

 dian originates before it, or scarcely more than oiie-iihh wav to the ptero- 

 .-tigma. The reticulation of the upper half of the wing is mostlv tetragonal, 

 and in the discoidal area ver\ open, while in the lower half of the wing it 

 is niostlv pentagonal, and dense apicallv : this results in part from the </rtf 

 Hiuiilifr of interposed supplementary sectors, <>f which there are several 

 between the ultraiiodal and nodal sectors, and several between each of the 

 following sectors as tar as the upper sector of the triangle; the upper of 

 these curve somewhat downward as they approach the apical border. The 

 po>tcostul 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 

 nodus is situated at an nmiMial distance outward, indeed HH( /,'/;/ far before 

 the Htiililli' of the wing (rather more than one-third the distance from tlje 

 base), and at a third of the distance from the arculus to the pterostigma. 

 The petiole terminates at some distance lirfurr the arculus and is verv slen- 

 der. The wing is rather full in the middle, and the apical half of the pos- 

 terior border is very full, the apex tailing 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 charac- 

 ters, such as the density of the reticulation. It seems indeed to be a verv 

 aberrant member 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 \Vorld, this is an additional instance of 

 neotropical 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 



VOL XIII 9 



