NYMPHALTNAE: BASILARC'IIIA AIICHIPPUS. 277 



Aiio^ust 7. Its mode of passing tlie winter, however, is the same in Mis- 

 souri and in West Virginia as in the north ; only Mr. Edwards says that 

 they always reach their second and sometimes their third stage before 

 hibernation, and he lias found them exposed as late as October 12. It is 

 a curious thing that we find in the caterpillars of the first brood no tendency 

 whatever to construct hibernaeula : here we have an instinct inherited by 

 alternate generations ; or only when the nightly chills or the desiccating 

 food indicate the coming of an unfriendly season. 



It is hardly pi'obable that the butterfly ever hibernates ; but ]Mr. Lintner 

 records one butterfly as seen on May 8 at Scoharie, New York. If Anosia 

 plexippus were not mistaken for this species, as Mr. Lintner himself thinks 

 possible, so early an apparition would surely indicate that the insect had 

 wintered either in the chrysalis or imago state. 



Habits, flight, etc This Initterfly is very fond of the juices of apples 

 drying in the sun and of over-ripe fruit. Jack has noticed it aligliting on 

 leaves curled by plant lice and drinking the sweets exuding from the car- 

 uncles of the Aphides. 



The flight of this butterfly is rather leisurely and sailing ; it moves irreg- 

 ularly from place to place, occasionally returning to the same spots. 



When at rest, the body is raised at an angle of from 30° to 35°, the 

 wings are closely compressed, the tip of the fore wings placed above the 

 middle of the abdomen and so concealed by the hinder pair as to leave un- 

 covered only six of the submarginal row of spots. The antennae are nearly 

 straight, having an almost imperceptible bend in the middle by which the 

 tips are slightly approximated ; when the insect is on a horizontal plane, 

 they are raised at an angle of about 15° with the body and spread about 

 70° ; but when the insect is in a perpendicular position, the head down- 

 ward, the divarication is only about 45°, and the antenna! tips about 13 

 mm. apart. 



Mimicry. There exists among North American butterflies no more 

 complete mimicry than is shown by the imago of this species for that of 

 Anosia. How close it is will appear at once by comparing the figures of the 

 two upon our first plate ; and how far it has departed from its ancestral 

 pattern and colors may be inferred on a comparison of figure 5 with the fig- 

 ures of the other forms of the genus on Plate 2, figures 5, 8 and 9. The 

 ground tint, which is almost identical in the other forms of Basilarchia, has 

 changed completely from a blue black to the deep orange, characteristic of 

 Anosia ; this has apparently been brought about by a complete 8uflfi.ision 

 (and perfect transference to the upper surface, as well) of the orange spots 

 which are found only at the liase and near the outer margin of the other 

 species, and ^\•hi('h are usually wholly distinct, or confluent only near the 

 tip of the fore wings. In the pattern of. the markings we find the nearest 

 approach to the form proserpina, which, as a hybrid of the other two New 

 England species, may possibly indicate moi-e cleaidy than either of them the 



