256 THE BUTTERFLIES OF NEW ENGLAND. 



The juvenile caterpillars differ from those fully grovvn in having a smooth 

 head and uniformly cylindrical body, subquadrate in cross section, studded 

 with numerous, equal, stellate, regularly disposed warts. 



The chrysalids are also of a peculiar shape, having the anterior half of 

 the body curved, the head thrust forward and downward and the thorax 

 considerably arched, while the abdomen scarcely tapers except at the 

 bluntly rounded extremity, and bears, on the second segment, a strongly 

 compressed dorsal projection, oddly resembling a "Roman" nose. It 

 appears to be slenderer than the chrysalis of Najas. 



The species of JBasilarchia differ from each other in the chrysalis state 

 again very slightly, and can with difhculty be distinguished ; an examination 

 of a considerable number of specimens shows me that there is considerable 

 variation in the same species in the form of the dorsal tubercle of the sec- 

 ond abdominal segment ; its anterior curve is perhaps a little more pro- 

 duced in archippus than in the other species. In archippus the basal 

 wing tubercle is produced to a minute, conical, pointed wart directed out- 

 ward ; in arthemis it is somewhat pointed but directed a little backward ; 

 while in astyanax it is rounded off or partially suppressed. Viewed from 

 aljove the portion of the cremaster lying within the marginal ridge is 

 nuich longer than broad in archippus, while in the other species it is 

 nearly square. Astyanax is perhaps a little stouter than the other species, 

 and more constricted at the metathorax on a dorsal aspect than either of 

 the other two. See also Riley, Can. ent. iii : 52, 117, and Lintner, Proc. 

 Ent. soc. Phil, iii : 63. 



The species are normally multiple brooded, the larva of the last brood 

 and sometimes of the preceding, when in its second or third stage (some- 

 times in the fourth) , constructing for itself a hibernaculum out of a leaf and 

 wintering therein ; it quits this in the spring before the leaves are fairly 

 out and the earliest butterflies appear, in New England, in June. A sec- 

 ond brood in August is usually less abundant than the preceding, so that 

 then the insects probably have a history similar to that of Nymphalis, as 

 given below. 



As before stated, some species of this genus, when in their perfect state, 

 are believed to mimic the coloration and design of other butterflies. 

 Doubleday was the first to point out this curious resemblance (Gen. diurn. 

 Lep., ii : 275) ; B. astyanax, he says : 



Is remarkable for entirely wantinsi the white fasciae so characteristic of the genus, 

 he upper surface of the wiugs being black, tlie extremities covered with blue scales^ 

 witli several subapical rows of black luuules ; ou the under side it is glossed with 

 purple, and elegantly ornamented with bright orange spots at the base and beyond the 

 middle of the wings. It bears, in fact, a singularly strong analogy in its colours to the 

 North American Tapilio pliilenor, whilst the allied species, L. disippus, (P. archippus 

 Cramer) bears an e(iually strong analogy to Danais archippus [plexippus] in its dark 

 orange-red colour, with a ))lack })order to all the wings, spotted with white. 



This subject is fully discussed elsewhere in this work. 



