1888.] 



155 



Species. 



2 a 



¥-* CD rf 



p.* 



02 a> 



It will be seen at once how easily mistakes may be made in tabu- 

 lating the species of Cerostoma by neural characters from an insufficient 

 series, moreover, it is not difficult to overrate the importance of slight 

 differences of neuration in determining the limits of genera, and 

 perhaps of families or sub-families. 



Here we find not only a few exceptional cases, but numerous in- 

 stances, in at least sis species of an accepted genus, in which the right 

 and left fore-wings of the same specimen differ from each other in the 

 arrangement of the apical veins. 



In the face of such evidence, it is surely no longer safe to regard 

 slight modifications of neuration, when observed in isolated specimens 

 only, as conclusively establishing the proper classification of the 

 species. Wrong as it would be wholly to neglect such evidence, it 

 can b'e accepted only in conjunction with other corroborating charac- 

 ters, and after careful elimination of all possible sources of error. 



Another question arises in connection with this subject, suggested 

 perhaps, by some remarks of Mr. E. Meyrick in his paper " On the 

 Classification of some Families of Tineina " (Trans. Ent. Soc, 1888, 

 119—131). 



In cases where the two apical veins are variably forked, separate, 

 or arising from a point in different specimens, or in opposite wings of 

 a single specimen of one and the same species, it may probably be 



