758 STUDIES IN AUSTRALIAN NEUROPTERA, Vl., 



Our study of the venation shows us that the cross-veins are 

 not preceded by trachejt?, and that they are to be considered as 

 a later addition to the main sclieme of venation. This appUes 

 more especially to the costal series of cross-veins and its continu- 

 ation, the terminal gradate series, which are not fully developed 

 in any other family, and are evidently comparatively recent 

 acquirements, correlated w itli the great enlargement of the costal 

 area. With regard to the discal and internal gradate series, it 

 must be evident that vaiiations in the amount and position of 

 the cross-veins formijig them will depend partly on the size of 

 the insect, and partly upon the number of branches of the radial 

 sector possessed by it; we should, therefore, be prepared to find 

 a great deal of variation in these characters. If, then, the 

 present system of classification should fail to stand the test that 

 we propose to apply to it, we shall be faced with the problem of 

 finding more reliable characters, on which to rebuild a sounder 

 arrangement of the species. 



Though it is not the purpose of this paper to deal exhaustively 

 with the non- Australian species, it will be first of all necessary 

 to call attention to certain errors and omissions in Navas' most 

 recent work. A paper that claims to be a monograph of a family 

 should surely contain a complete bibliography of all the more 

 important papers concerning it, and should also at least list, if 

 not describe, all the known species. But I find that Navas 

 omits from his work all reference to two of McLachlan's most 

 important papers (9, 10), in which that fine entomologist described 

 a new South African species on the one hand, and the only 

 known Burmese species on the other (Fsi/chopsis mar shall i^oLi., 

 and Ps. binnana McL., respectively). Consequently, Navas 

 gives only four species instead of five for South Africa (unless, 

 indeed, one of his own species is synonymous with McLachlan's I), 

 and is quite unaware that a Burmese species exists at all I As 

 there are only fifteen species known altogether, it will be seen 

 that these omissions are veiy serious for a monograph. 



We must now note some further errors of equal gravity. In 

 1910, Navas described specimens of Pst/chopsis elegans (Guerin), 



