DISTRIBUTION OF BUTTERFLIES IN THE NEW WORLD 323 



DISTRIBUTION OF MAJOR GROUPS (EXCLUSIVE OF THE 



HESPERIIDAE) 



The distribution of the major taxonomic groups In North and 

 South America is shown by a series of histograms (Figs. 1-19). The 

 histograms are constructed In the following manner. Blocks indi- 

 cating distributional range are drawn on a scale from left = north to 

 right = south, reading from 82° N. Lat. to 55° S. Lat. Each block 

 covers 5° of latitude and 1,000 meters of elevation above sea level. 

 For example, in the charts on distribution of the Paplllonldae (Figs. 

 2-3), if a species exists at an elevation of 1,500 meters at 46° S. 

 Lat., this fact is indicated by a block extending from right to left 

 at 45°-50° S. Lat. and up and down from 1,000 to 2,000 meters. On 

 some histograms, where the data warrant and the distributional 

 relations are thereby clarified, the bars are terminated between the 

 arbitrary 5° class limits, and, occasionally, the altltudlnal limits are 

 set at 500-meter intervals. Where the ranges are disjunct, a line has 

 been drawn to connect the base of the separated parts. Where the 

 altltudlnal information on a genus Is inadequate, the latitudinal 

 distribution is indicated by a thin line. 



For comparison with these ranges, a histogram is shown at the 

 top of each figure to indicate the extent of land and habitat avail- 

 able in North and South America, for the absence of a butterfly 

 group in any area may be caused by the absence of a particular 

 elevation at a certain latitude so that no habitat Is available there. 



This comparative chart is drawn In the same way as those for the 

 butterflies, with the exception that blocks of 1° latitude are used in- 

 stead of 5°. Also, since in some areas high elevations are represented 

 solely by a few mountain peaks, these are indicated by the sign A , 

 while short ranges are Indicated by H, mountain passes (breaks In 

 distributional ranges) are indicated by U, and three areas of nearly 

 complete break in the cordillera are indicated by v . 



All areas potentially inhabitable by butterflies are shaded ; areas 

 of perpetual frost or cold, in Greenland and southern Chile, are 

 unshaded. 



Generic names of the butterflies are taken from Seitz's Macro- 

 lepidoptera of the World, even though it is now known that many of 

 these are not correctly used. The reason for this usage is to avoid 

 difficulty in identification due to conflicting opinions. 



From the chart of the families (Fig. 1) it can be seen that the 



