AMERICAN LEPIDOPTERA. 319 



in some cases, where the peculiarity seems to be in the process of 

 development, or where perhaps the species is outgrowing it. Some- 

 times it is large and prominent, consisting of an unsealed vitreous 

 surface, at times with a peculiar gland within it. 



There is wide variation in the structure of the antennae not only 

 in that bipectinate, lamelate, fascicled, ciliate, filiform and flattened 

 forms are found, but also in the location of the various appendages. 

 In many species the pectinations are at the summits, in others at the 

 bases of the segments. The rule is not invariable, but generally the 

 species having the fovea on the fore wings of the males, have also 

 the pectinations or fascicles on the top of the segments of the antennae. 



Apart from the elements of structure upon which the subfamily 

 is founded, there is among the species a very wide range of variation. 

 The palpi, clypeus, antennae, legs, thorax, abdomen and wings vary 

 greatly ; especially is the venation subject to variation not only in the 

 diflferent species, but in the individual species. In view of this, in the 

 main, very little dependence can be placed upon the relations of veins 

 9, 10, 11 and 12 to each other in the fore wings. Not infrequently an 

 extra vein (vein 13) is found, and very frequently 11 is present or 

 absent in different specimens of the same species; 9, 10, 11 and 12 

 anastomose with each other, or are separate in the individuals of one 

 species, and as a consequence very little use can be made of them in 

 classification. The position of the bases of the veins are much less 

 variable. The hind wings are less changeable in venation than the 

 fore wings, but the comparative positions of 3 and 4, as well as 6 

 and 7, cannot be relied upon within narrow limits. 



Synopsis of Genera. 



1. Fore wiugs of % with fovea below at base of la 2. 



Fore wings of % without fovea below at base of la 36. 



2. Antenna' of % bipectinate 3. 



. Antennae of % not bipectinate 30. 



3. Tongue absent, or very short 4. 



Tongue developed, at least one-half thorax 5. 



4. Hind tibiae with one pair of spurs 63. Si'acophora. 



Hind tibife with two pairs of spurs 34. Ami lapis. 



5. Fore wings with discal scale tuft 44. Tornos. 



Fore wings without discal scale tuft 6. 



6. Clypeus tuberded 7. 



Clypeus not tubercled 11. 



7. Fore tibise clawed 8. 



Fore tibiae not clawed 49. Ccenocharis. 



TKANS. AM. ENT. SOC. XXIII. SEPTEMBEK, 1896. 



