299 



and Crontbrugghia in nature but from Tutt's remarks we judge these 

 genera to be of the same character as numerous others of his, and 

 tlierefore happily suppressed. We regard a genus as a systematic unit, 

 not a biological division, and feel that when it loses its value for classi- 

 fication it has lost its right to exist. 



The male genitalia in this genus show two forms of harpes, the 

 one long, heavily chitinized and curved, the other weak and mem- 

 branous. In our species and in the four European species which we 

 have seen, ri:;., didactylus, hicracii, pilosellae and parvidactylns, those 

 species which have the terminal tuft on the second joint of the palpi 

 are furnished with the second type, and those which lack this tuft 

 have strong genitalia. These characters apparently divide the genus 

 into two well marked groups, but we do not regard them as worthy of 

 generic rank. 



Key to the Species 



1. Second joint of palpi with a distal tuft projecting beneath third. .rfc/fUt'iirtVui 

 Palpi slender ; second joint without tuft 2 



2. Median spurs of hind tibiae attached three-fifths or more of length of 



joint from its base ^ 



These spurs very close to middle of tibia 4 



3. Dorsal surface of abdomen with divergent white lines reaching from 



front to hind margins on several segment?, widening behind ningoris 



White lines on dorsal surface of abdomen obsolete at least anteriorly, 

 usually limited to a few scales in posterior margins of segments. A 

 much darker species raptor 



4. Light brown; abdomen without contrasting pure white marks above 



pcriscelidttctylus 



Ven' dark brown; abdomen with some pure white above except in dark- 

 est specimens ^ 



5. Fourth abdominal segment brown above, the adjacent segments with 



white marks tenuidactylus 



Fourth segment white above, others white marked cygnus 



1. Pterophorus periscelidactvlus Fitch. PI. XLI, fig. 4. PI. 



XLIX, fig. 5. 

 Pterophorus periscelidactylus Fitch, Trans. N. Y. Agr. Soc. XIV, 843, 1854 

 (biol.). 



Id.. 1st. Rept. Ent. N. Y. 139, 1854 (biol.). 



Morris, Cat. Lep. N. A. 54, 1860. 



Walker, List Lep. Ins. B. M. XXX, 940, 1864. 



Riley, 1st Mo. Rept. 137, pi. II, ff. 15, 16, 1869 (biol). 



Id., Am. Ent. II, 234, f^g. 148, 1870. 



Id., 3rd. Mo. Rept. 65, fig. 27, 1871 (biol.). 



