1796 BUTTERFLIES BEYOND NEW ENGLAND. 



Last stage. Head subovate, depressed at top, the height to the breadth as eight to 

 seven ; color gray green, thiclvly covered witli tubercles like those on body, small and 

 large; among these are larger ones, three on either lobe in triangle, so disposed as 

 to make a row of four across the forehead; these are white, with a brown rim about 

 base, or the inner pair are white, the others black; on each vertex a triplex process as 

 described at fourth stage, black; along the back and sides white processes, of which 

 a duplex or bifld cue, taller than elsewhere, stands on either suture; ocelli black. 

 Body stout anteriorly, thickest at the second and third thoracic segments, tapering on 

 dorsum and sides to the ninth abdominal segment, the end of the latter rounded and 

 the dorsum much curved ; color gray green, the first thoracic segment darker green; 

 usually marked by patches of black on dorsum or sides of segments, after the second 

 abdominal segment, but some examples have little, or it is pale colored, and others 

 have none at all ; entire upper surface studded with low, rounded tubercles, varying in 

 size, but always small, placed on the cross ridges ; these are whiter than the ground 

 color, and from each proceeds a very short, straight white hair; under side, legs and 

 prolegs a shade lighter than the upper; tlie first, second, seventh and eighth abdominal 

 segments crossed by tubercles. Length, 33 mm. French gives the length of mature 

 larva as 39 mm., and probably wild examples are larger thau my bred ones. 



Chrysalis. Shape much as in Auosia plexippus, the last segments reti-acted in the 

 same way, so that the abdomen is greatly shortened, and the shape that of a dome; the 

 head case short, narrow at top, and beveled to a sharp, slightly incurved ridge, the 

 sides sloping, mesonotum prominent, carinated, rising posteriorly to a rounded point, 

 the slope to top of head regular, and at about 45° ; the depression behind shallow 

 and broad ; the dorsal edges of wing cases prominent ; the sides excavated ; color light 

 green, granulated with whitish; the edges of wing case and top of head case whitish. 

 Length, 16.5 mm. ; breadth at mesouotum, 9.7 mm. ; at abdomen, 10.2 mm. 



The Mississippi Valley is the home of this butterfly, where it extends 

 westward to the Great Plains, but not far to the eastward, and from south- 

 ern Illinois to the Gulf. It is shy and difficult of capture, its flight 

 exceedingly rapid "with a dry, whistling sound. Although easily alarmed, 

 it seldom leaves a favorite locality, but continues to fly about until danger 

 has passed. It is curious as the Vanessas, and I have several times taken 

 it by standing motionless, when after numberless rapid circlings and dashes 

 about me, it would suddenly alight on the ring of my net." (Edwards.) 



Until recently our knowledge of the life history of this butterfly was due 

 principally to the field observations of Mr. Muhleman and Dr. Haj'- 

 hurst, both of whom were satisfied that tliere is but a single brood annually, 

 which appears at the very end of the season at end of September and 

 October, and goes into hibernation early in November. Dr. Hayhurst 

 remarks "the food plant does not sprout up and leaf sufficiently to support 

 the larva before 1st of July." But latterly Mr. Rowley, who furnished 

 Mr. Edwards with the material for his fuller study of the early stages, 

 asserts that there are at least two broods of the imago, and that there is a 

 decided seasonal dimorphism in the two broods of the female. 



The larva feeds on an annual, Croton capitatum, one of the Euphor- 

 biaceae, which is tolerably common in Illinois, Missouri, Kentucky, and 

 westward, where it is known by the name of goat-weed (Riley), and also 

 on C. monanthogynum, as the butterfly is to be found where the first plant 



