2l6 ENTOMOLOGICAL NEWS. [May, *I2 



and it now seems probable that R. mortua is another variety of 

 the same species. 



The species problem among fossil insects is a difficult one. 

 Handlirsch attempts to solve it by treating each distinguishable 

 form as a distinct species; thus in Contributions to Canadian 

 Palaeontology, Vol. II, part III (1910) he describes twenty 

 species of the Bibionid genus Penthetria from the Tertiary 

 rocks of British Columbia, although it is surely improbable that 

 they are all specifically distinct. Such a plan has the advan- 

 tage of separating and defining all the available structural 

 types, but it must result in misleading statistics if carried far. 

 It seems better to give specific names only to forms which are 

 probably distinct, using the same criteria as are considered valid 

 in the case of their nearest living allies, and to distinguish others 

 as varieties, with either varietal names or letters of the alpha- 

 bet. 



Handlirsch, in the work just cited, has an interesting discus- 

 sion of the fossil Raphidiidae, in which he proposes new generic 

 names for two of the Florissant species. Megaraphidia clegans, 

 Raphidia exhumata and R. mortua all agree in having the up- 

 per branch of the radial sector simple until it reaches the end, 

 or nearly the end, of the cell in the fork of the sector ; a con- 

 dition very different from that found in the living R. oblita and 

 R. notata. In the living R. rhodopica, however, the condition 

 in this respect is as in the fossils. R. rhodopica differs con- 

 spicuously from the fossils in the much shorter lower side of 

 the pterostigma. In the basal stalk of M-Cu R. rhodopica dif- 

 fers from the fossils, which herein agree with R. oblita and R. 

 notata. The cross-vein descending from the lower side of the 

 pterostigma is a character which separates the fossils from the 

 recent species ; in the latter the cross-vein is beyond the stigma, 

 or in R. rhodopica descending from its end. All things con- 

 sidered, it seems impracticable to separate R. exhumata and 

 mortua from Raphidia, and I am now doubtful whether Me- 

 garaphidia is more than a subgenus, although Handlirsch says 

 it is "undoubtedly a well-founded genus." 



