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Vol. XXXIX. LONDON, NOVEMBER, 1907. No. 11. 



A FOSSIL BUTTERFLY OF THE GENUS CHLORIPPE. 



BY T. D. A. COCKERELL, UNIVERSITY OF COLORADO. 



Among tlie interesting specimens found in the miocene shales of 

 Florissant, Colorado, is a well-preserved butterfly, collected by my wife. It 

 shows the head and thorax, one antenna, and the anterior wings, all well 

 preserved. The study of it has raised some questions as to the evolution 

 of the markings and wing-form in Chlorippe and its allies, and I venture 

 to hope that a statement of these may produce some fruitful discussion. 



Chlorippe Wi//natt(E, n. sp. 

 Expanse, 64 mm.; length of anterior wing, 30 mm.; antennre about 

 T3 nmi., gradually broadening apically, the club not at all abrupt ; about 

 4 mm. may be considered to be club, but it is hard to say where it 

 begins. Palpi well developed, apparently as m C/iiorippe. Thorax 

 robust, dark. Wings with the outHne about as in C. alicia, S 1 but the 

 apical point between the radials is sharper and longer, being quite 

 suggestive of that part in Vanessa, and exactly agreeing with the same 

 structure in the South American Chlorippe sultana $ ; wing as preserved 

 pale sepia brown, with whitish spots, these latter corresponding to those 

 in Chlorippe, in a general way, but differing in the arrangement. In the 

 apical field the spots are small and round ; tlie three outer ones, instead 

 of forming the corners of a triangle, are arranged in a line, which is slightly 

 curved outwards, and parallel with the outer margin. On the other 

 hand, the three inner ones, which in Chlorippe form a curved or oblique 

 line or band, are. so arranged that the two lower are close together, one 

 above the other, while- the third or upper is far basad, the interval between 

 the upper and middle one being about the same as that between the 

 middle inner and corresponding outer. The four large spots in the 

 median interspaces are all very distinct, 2 mm. or over in diameter; none 

 of them are ocelli. In modern Chlorippe the upper inner one is usually 

 quite small, but in the fossil it is large like the lower, and is so placed 

 that a line drawn through the two inner ones points almost accurately to 

 the apex of the wing. Of the spots between the median and submedian 

 veins, both are somewhat diffused, though distinct, and the outer is 



