150 BULLETIN UNITED STATES GEOLOGICAL SUKVEY. 



paler in color than any of tlieir eastern congeners and not larger. 

 Uiirynome, a genus founded on two species, found as yet only in Colo, 

 rado, does not differ from the allied Bucculatrix in size or coloration- 

 And the two or three species of Nepticula (or Trifurcula f) are rare and 

 known only by their mines. 



These are the only genera which are known to be represented among 

 the Tineina of Colorado, and notwithstanding the cases of S. gigantella, 

 BatracJiedra sp. ?, and Lyonetia alniella, the weight of evidence, such 

 as it is, does not support the theory suggested, and if these three spe- 

 cies seem to lend it any support, it would yet require the accumula- 

 tion of a very much greater number of instances of increased size or pe- 

 ripheral development^ or depth, or intensity of color, to demonstrate that 

 these things have any necessary connection with the western habitat of 

 species. 



The Tioieina, however, are generally not well adapted either to the 

 proof or disproof of such a theory, so far as size and increase of periph- 

 eral development are concerned, since their minute size would make it 

 difficult to detect any such small increase as would be likely to occur 

 from such a cause, and if detected it might be considered to be within 

 the range of variation of the species. As to color, however, they afford 

 as good an opportunity of testing the theory as any other group, and 

 here their testimony is decidedly against it. 



Some of the species above mentioned are noL yet known by published 

 descriptions. 



