AMERICAN LEFIDOPTERA. 9 



leaving only the apex free. The orbicular and claviform are 

 usually white. The reniform is marked by white margining spots 

 which are sometimes absent. 



Nitela is the first of the mouse-gray species and is a somewhat 

 variable form. The t. p. line is always distinct, accompanied by a 

 whitish line, beyond which a pale cloud extends a variable distance ; 

 but the line itself is not so abruptly beut as in the brown species. 

 In all cases the line is evenly oblique or almost rigid, and in many 

 instances it seems to run directly into the costa ; but not infrequently 

 it bends or curves inwardly opposite the upper part of the cell and 

 runs evenly into the costa. The ordinary spots may be present and 

 white marked, or they may be scarcely traceable. The s. t. line is 

 always traceable and sometimes distinctly marked by white scales. 



Nelita is closely allied but is smaller, and the t. p. line, which is 

 much less evident, runs outwardly to the inner margin just within 

 the anal angle. 



Necopina is larger than the two just mentioned and almost with- 

 out markings. The t. p. line is barely traceable by a scattering of 

 pale scales, and sometimes traces of the ordinary spots can be seen ; 

 but the s t. line is not visible in any example seen by me. 



In the remainder of the species the t. p. line may or may not be 

 geminate, but is usually lunulate, crenulate or otherwise irregular: 

 it is curved and bent over the cell and is somewhat drawn in below, 

 never even, as in the preceding series. 



Linipida and cerussata are very dark, blackish brown species, 

 with white ordinary spots, and join naturally to the dark, mouse- 

 gray species of the preceding series. 



Limpida is moderate in size or rather small, and has the reniform 

 quite broad and normally developed. In the male the mark is 

 entirely white, though broken into blotches. 



Cerussata is much larger, the reniform longer and narrower, the 

 white spots grouped around a central, narrow, yellow line or cres- 

 cent. The difference at first sight is not great, and I would not 

 have been inclined to allow so much weight; but at this point the 

 uniformity in male sexual parts is broken in a remarkable way. 

 The harpes here are broad— very small for so large an insect — the 

 tip is obtuse, the upper angle rounded and set with a few short, 

 very stout spines, the lower a very little produced. The clasper is 

 short, very stout, cylindrical, a little curved and with an obtuse tip. 



TRANS. AM. KNT. SOC. XXVI. (2) MAY. 1899. 



