62 FOSSIL BUTTERTLraS. 



above it ; following the principal dark band are two alternating sets of dark and 

 light, narrow, inconspicuous, transverse stripes, more or less confused in the middle 

 of the wing, the dark bands broadening and deepening at the nervures, breaking 

 the paler bands to a greater or less extent into broad transverse spots; the fringe 

 appears to be as on the fore wings. Judging from the form of the last abdominal 

 segment, and the great size of the abdomen, this specimen was probably a female. 

 Length of fore wing, 2o'"'"'; breadth of the same, 14'3"""-; length of antennai, about 

 gmm.. breadth of antenna) in middle of stem, •2°""-; breadth of antenna; toward tip 

 of club, -S""-. 



Tertiaries of Ais. Collection of Professor Heer; Zurich, Switzerland. 



URBICOL^ — SESPERIDES. 



THANATITES Scuddek. 



Very much of the general appearance of Thanaos Boisd. (PL III, fig. 2) but 

 with somewhat differently formed wings and markings which will not accord with 

 those of the latter genus, although the two genera are certainly nearly allied. 



The body (PI. HI, fig. 12) is fuUy as stout as in Thanaos (PI. Ill, fig. 11), 

 the tongue at least as long as the thorax, the eyes ovate and larger, than in 

 Thanaos, and the palpi with the terminal joint proportionally larger, which is an 

 unusual feature in the Urbicolse. The legs are apparently short, the wings ample. 

 The costal margin of the fore wings is nearly straight, being scarcely arched on 

 the apical half, the upper half of outer border as in Thanaos, the rest not pre- 

 served; the costal fold of the male is narrow and extends a very little beyond the 

 middle of the costal border, while in Thanaos it reaches considerably further; the 

 hind wings have the general shape of Thanaos, but the upper outer angle is much 

 more produced, and the base of the costal border is arched only to the degi-ee that 

 the apex is, and the portion between them is but slightly convex; the outer border 

 is almost precisely as in Thanaos and the inner border is, doubtless, folded in the 

 fossil so as to conceal its true character. Yeiy little of the neuration can be 

 determined, and what can be made out is comparatively imimportant and agrees 

 with the neuration of Thanaos; the third superior subcostal nervnle strikes the 



