SPILAPTBRA. 58 



wrong in other details, we are compelled to assign the specimen to the family 

 Breyeriidae, and doubtfully to the genus Breyerla, with which it seems in agreement. 



Family Spilapterid^: (Brongniart), Handlirsch. 

 1906. Handlirsch, Die Fossilen Insekten, p. 101. 



Radial sector more or less branched ; median divided into two main branches, 

 the outer much divided ; cubitus with an outer branch sending numerous twigs to 

 the inner margin. Intercostal area occupied by a series of straight cross-nervures. 



The family Spilapteridae, founded by Brongniart in 1885, has been re-defined 

 by Handlirsch and Lameere. The latter extended the group to include species 

 which Brongniart had placed partly in the family Platypteridas and partly in 

 Protephemeri<he. All the forms thus brought together by Handlirsch agree in 

 the possession of a typical paheodictyopteroid neuratiou and the general characters 

 enumerated above. 



Lameere ('Bull. Mus. Hist. Nat. Paris,' 1917, no. 1), who rejects Handlirsch's 

 views and classifications (see above, p. 15), has remodelled the family and given it 

 a new significance 1 . He is of opinion that the genera Lamproptilia, Epitethe, 

 Becquerelia, Palasoptilas, Compsone'ara, Spiloptilus, Homaloneura, Graphiptdus and 

 Spilaptera form a natural family, the Spilapteridas, in which a progressive 

 evolution in the longitudinal venation can be observed. The family is regarded 

 as linked to that of Megasecopteridae through the genus Becquerelia, and to the 

 Protephemerida? through the genus Apopappus. The three families are then 

 grouped in his new order, Ephemeroptera. Such a- classification is based on the 

 belief that a perfect evolutionary sequence can be made out. Unfortunately, in 

 presenting this classification, Lameere gives only a summary of his reasons and 

 evidence, and it is not possible to criticise his argument. It is, to say the least, 

 very doubtful if, in the present state of knowledge, we can judge relationships 

 always correctly, Avhile the sequence of evolution is still more difficult. 



Handlirsch has acknowledged that he is unable to undertake any division of 

 the family Spilapteridae, as he understands it, and is content to await the discovery 

 of the bodies of these insects for a fuller knowledge of the family. As the more 

 rational view, Handlirsch's definition of the family is adopted. 



Genus SPILAPTERA, Brongniart. 



1885. Sjiilaptera, Brongniart, Bull. Sue. Amis Sci. Nat. Rouen [3], ann. xxi, p. 63. 



Generic Characters. — Insects closely resembling PaJseopjtilus ; fore-wings 

 narrower basally than the hind-wings ; body slender. 



