Tinema of the Ceiiiral United States. 101 



and is not visible on the upper surface until the upper cuticle begins 

 to die, when the larva is fully grown. The mine of L. helianihivorella 

 is more than twice as large as that of amhrodceella, and is most distinct 

 on the upper surface, when it produces a tubercular swelling. 



Second— the larva of amhrosiaella has the head obscurely streaked 

 and clouded with fuscous. I have never found these markings on the 

 head of the larva of helianthivoreUa. ♦ 



Third — the imago of heliantluvorella has a small white spot on the 

 dorsal margin of the primaries, which is wanting in ambroskceUa. The 

 costal and dorsal streaks, which in avibrosiceella are simply white, have 

 a brilliant metallic gh)ss in helianthivoreUa, and the latter species is 

 the largest, having an alar ex. one twentieth of an inch greater than 

 ambrosiceella. This appears to be a small difference, but when all other 

 parts of the body are developed in the same proportion, it makes a 

 very considerable ; and when the insects are placed side by side, it 

 makes a very striking difference in the size and appearance of the m- 

 sects. I have compared numerous specimens of the two species, and 

 notwithstanding their close resemblance, I have no doubt that they 

 should be considered distinct species. 



L. argentinotella, Clem. 



In a single instance I have found this species mining the upper sur- 

 face of elm leaves. Neither the mine, nor larva, nor insect, differed 

 fj-om those of the under surface of the same leaf. Prof. Frey, of Zurich, 

 has strangely confounded it with L. uhiella, Cham. 



L. alba-notella (n. sp.) 



Head, palpi and antenna; glistening snow white ; extreme apex of 

 the antennae dark brown ; thorax white ; primaries brilliant golden, 

 rather pale, with a short, median, white basal streak, faintly dark mar- 

 gined toward the costa ; basal fourth of the costa white (the base of 

 the wings is also white, I think, but is a little rubbed, so that I can 

 not be certain) ; four rather large, snow white costal streaks, the first 

 of which is just before the middle of the costa, and the fourth is near 

 the apex; three snow white, rather large dorsal streaks, the first of 

 which is a little before the first costal streak, and the second and third 

 of which are respectively opposite the second and third costal streaks, 

 with which they sometimes meet, so as to form fasciae First costal 

 and first dorsal somewhat oblique. First three costal and the three 



