BY E. MEYRICK. 595 



marked fovea ; 10 sometimes connected with 9, 11 sometimes out 

 of 10, sometimes anastomosing with 12, sometimes absent (coin- 

 cident with 10). Hind wings normal. 



A large and cosmopolitan genus, of which the species are 

 sometimes difficult to determine, owing to their obscure and 

 similar colouring. The structural differences and the colour of 

 the face should be carefully observed, and often give easy 

 distinguishing characters. The neuration varies considerably ; in 

 Australia the species fall naturally into two groups, in one of 

 which veins 10 and 11 are stalked or coincident, whilst in the 

 other they are separate, and I formerly supposed that these groups 

 could be maintained as distinct genera, but a wide study of exotic 

 species of the genus has shown me that in them the two types of 

 structure not unfrequently occur in different individuals of the 

 same species ; hence their discrimination is impossible. 



In the following tabulation S. despicata is not included, as its 

 characters are insufficiently known ; it is an inconspicuous 

 brownish species, without any striking points. Owing to insuffi- 

 ciency of material, I cannot be positive that the characters on 

 which stress is laid in the tabulation are constantly reliable, and 

 care should always be taken to note the several points of difference 

 which usually occur between any two species, and- not to depend 

 on one exclusively ; the specific separation of these insects will 

 then be found easier than is supposed. 



1. Fore wings with veins 10 and 11 separate 2. 

 Forewings with veins 10 and 11 stalked 



or coincident 7. 



2. Face wholly blackish 38. argoplaca. 



Face not wholly blackish 3. 



3. Antennae in <J with apical J simple 37. euboliaria. 



Antennae in $ with apical f or more 



simple 4. 



4. Face with broad blackish median bar 5. 



Face with blackish median bar incomplete 



or obsolete ..... 6. 



39 



