REVISION OF SPECIES OF THE GENUS AGliOTIS. 11 



groups lire fornieil in tUis genus. In the first, of wiiicli sulxjnthica is 

 typical the orbicular is opeu above, V-shaped; in the second, of which 

 venerabiUs is typical, the orbicular is complete. 



Porosagrotis is applied to a series of forms of usually pale colors, 

 moderately long and narrow primaries in which the ai)ices are distinct, 

 an<l in which the clavifom is rarely, the basal dash never, i)reseut. 

 They ditfer in habitus very greatly from the preceding, and immvnula is 

 tyi)ical. 



The remainder of the species, over one-third of the entire number, 

 are referable to the genus Canieades,o{ which mocrcm and citricolor are 

 typical. They agree in the tuberculate front, brush-like (bristled) male 

 antenna?, heavily spinose fore-tibise, and finally in the bifurcate clasper 

 of the male genitalia. 



This large series of species is divisible into five fairly well-marked 

 groups. Group ivilsonil has primaries with depressed, somewhat con- 

 cave costa, the apices somewhat produced, and thus differs from all the 

 others, in which the costa is normally straight or slightly convex. 

 Group quadridenfata is distinguished by the pale lines marking veins, 

 three and four and six and seven and variably indenting the terminal 

 space. • 



Group messoria is recognizable by the very evident median shade 

 crossing the outer portion of median space, and forming often the 

 only prominent bit of raaculation in the species. Group intijclirous 

 is largely negative, containing species which have no distinctive char- 

 acters referring them to other groups. Finallj^, group tcssellata con- 

 tains those species in which the cell is black, or of some darker shade 

 than ground color, between the ordinary spots. A number of species 

 which are not referred to at all in this paper, but which appear in Mr. 

 Grote's list, were not properly referable to Agrotis, even under the vague 

 definition which allowed such a loose assemblage. 



it is suggestive that so large a proportion of our species are from the 

 western part of our country, and that those species are mostly referable 

 to those genera in which the front is modified in some way and the tibial 

 armature heavy. In fact the distinctive character of the western fauna 

 is shown in the very predominance, and sometimes abnormal develop- 

 ment of tibial and clypeal armature. The great preponderance of pale 

 or bright colors of the species of Colorado, New Mexico, Arizona, and 

 Utah is also worthy of note and mny allow of some interesting con- 

 clusions when the facts are more completely' ascertained and collated. 

 I have attempted few generalizations since the bringing of order out of 

 the chaos of species has been a task so great and spread over so long a 

 period that the comprehensive view of the forms as a whole has been 

 obscured. The scheme above outlined is capable of more definite and 

 comprehensive statement in tabular form. 



