BY E. METRICK, B.A. 417 



(genera 1-60) tliis vein terminates in the liindmargin or apex, in 

 the second (genera 61-70) in the costa. Usually this point is 

 easily discernible, but occasionally the wing is so rounded that it 

 is hard to determine where the apex really is ; for this allowance 

 must be made. The important points of neuration can be made 

 out easily in all but the smallest species on the underside without 

 unsealing ; I have however denuded for examination specimens 

 of 300 of the species described. Xext to this the antennal 

 characters are most important, especially the presence or absence 

 of the basal pecten. This structure is fragile and liable to 

 denudation, so that observation of more than one specimen is 

 needed to ensure accuracy ; yet in species which possess this 

 pecten, it is uncommon to find even worn specimens showing no 

 trace of it. The length of the antennal ciliations is also of con- 

 siderable value. Other important points are the approximation 

 of vein 5 of the hindwings to 4 at base, the scaling and length of 

 the labial palpi, the possession of a thoracic crest, and the form 

 of the hindwings with the relative length of their cilia. The 

 maxillary palpi and ocelli are practically identical throughout 

 the family, and though occasionally obsolete, offer in my opinion 

 no tangible generic characters. 



In the following descriptions, a number placed after the 

 description of the antennal ciliations indicates the length of the 

 ciliations in terms of the breadth of the stalk of the antennae ; e. 

 g., 3-5 signifies that the ciliations are from three to five times as 

 long as the breadth of the antennal stalk. Similarly, a number 

 after the cilia of the hindwings denotes the length of the cilia in 

 terms of the breadth of the hindwings. At the request of Prof. 

 Zeller, I have given a Latin diagnosis of each species. The 

 measurements I shall give henceforth in millimetres (roughly, 

 25 mm. = 1 inch), which are universally understood, and not 

 liable to misinterpretation. At the end of the family an index 

 of the specific names and synonyms will be added, and 

 reference made to such published descriptions of AValker and 



