436 'J'HE BUTTERFLIES OF NEW EN(iLANI). 



The eo-o-s are very short ovate, broad at the base, furnished with very 

 prominent laminate ribs, which increase in height toward the summit wliere 

 they terminate suddenly; these ribs vary in number in the two sections, 

 beino- more numerous (fourteen to nineteen) in Neopyrameis than in Pyra- 

 meis (nine). 



The juvenile larvae have a smooth head with long hairs irregularly 

 scattered, and a uniform body supplied with three longitudinal rows of 

 little warts above the spiracles, two more nearly on a line with them and 

 two just below, — each wart emitting a long, tapering hair. 



The full-grown caterpillars are brown, varying from yellow to black, 

 with a pale interrupted lateral band and sometimes a lateral row of white 

 spots on most of the abdominal segments ; they are also furnished with 

 bristly spines arranged in eleven regular longitudinal rows. 



The chrysalids are not so strongly angulated as those of the preceding 

 •••enus and are furnished with prominent ocellar tubercles ; they are gener- 

 ally more or less olivaceous and ornamented with gilded nacreous spots. 



EXCURSUS XIIL— BUTTERFLIES COMMON TO THE OLD 

 AND THE NEW WORLD; WHERE DID THEY 

 ORIGINATED 



Dank euch, alleikleinste Leben 

 Kinder tier verjiiugten Monde ! 

 Deren Wunderliildung 

 Farben und Geschiifte, 

 Froh niein forsdiend Ang' besali. 



Denis. 



If we bear in mind the continuity of land between South America and 

 North America, we shall not be surprised at finding, at least along the 

 borders, some butterflies which are foimd on both continents ; but con- 

 sidering what wide oceans separate on either side the Old World and 

 the New, and that their points of contiguity are in extreme northern 

 latitudes, we might expect a greater absence of Old World forms in 

 North America. Yet if we separate from the bulk of butterflies of 

 this continent those which are found south of the Canadian border and 

 east of the Rocky Mountains, we shall find, out of the somewhat less than 

 two hundred and fifty species occurring therein, not over a dozen which 

 may be fairly considered identical with butterflies found in the Old World, 

 whether in Europe or in Asia. The identity of some of these, many 

 writers have questioned ; about some there is no doubt whatever, while 

 there are others which approach in appearance those of the Old World so 

 closely that naturalists are still in dispute concerning them. Let us con- 

 sider a few of these separately, that we may gain some idea as to the 

 nature of their peculiar distribution. 



