SPILAITKRA. 58 



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

 Breyeriidae, and doubtfully to the genus ///T///- rin, Avith which it, seems in agreement. 



Family Snr.AiTKUiD.i-: (nro^j^m't), Handlirsch. 

 liioti. Hanillirscb, Die Fossilpn Inseklen, i>. 1(11. 



< I 



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 bv a, series of straight cross-nervares. 



The family Spilapteridae, founded bv Hronguiart in 1885, has been re-defined 

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

 which Hrongniart had placed partly in the family Platypterida? and partly in 

 Protephemeriihe. All the forms thus brought together by Handlirsch agree in 

 the possession of a typical palaeodictyopteroid neuration and the general characters 

 enumerated above. 



Lameere ('Hull. Mas. Hist. Nat. Paris,' 1017, no. 1), Avho rejects Handlirsch's 

 vieAvs and classifications (see above, p. I-")), has remodelled the family and given it 

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

 Becquerelia, Palseoptilus, Compsoneura, Spiloptilus, Homaloneura, Graphiptilus and 

 Kliiliiptri-a form a natural family, the Spilapteridae, 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 

 Protephemeridae through the genus Ajinjxiji/iii*. 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, Ave can judge relationships 

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



Handlirsch has acknowledged that he is unable to undertake an\' division of 

 the family Spilapteridse, as he understands it, and is content to aAvait the discovery 

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

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



Genus SPILAPTERA, Brougniart. 

 1885. Spilaijtera, Broujjiiiart, Bull. S.>r. Amis Sci. Nat. Roneii [3], ;mu. xxi, p. 63. 



< ti'iii'ftf Characters. Insects closely resembling Pdl&uptilim ; fore-wings 

 narrower basally than the hind- wings ; body slender. 



