534 PROCEEDINGS OF THE NATIONAL MUSEUM vol. eo 



1 $ . Trinidad, British West Indies. Montsereat, 1 $ (W. 

 Schaus). Cuba: No. further data, 1 5 (W. Schaus). 



Notes. — This insect is extraordinarily constant throughout its enor- 

 mous range, and aberrations are rare. Most of the numerous speci- 

 mens from Polynesia that I have examined, all more or less worn, 

 are unusually dull in color, but this appears to be due simply to 

 fading in intense sunlight. Old individuals from the eastern United 

 States and from the Gulf coast are often equally dull. 



In the Old World Tropics this northern subspecies shows no ten- 

 dency to assume the characters of its tropical representative {nugal- 

 ippe) in America. 



Regarding Danaiis plexippus as it appears in Central America 

 Godman and Salvin wrote : 



Central-American specimens, as a rule, agree closely witli North-American 

 ones in having the spots toward the apex of the anterior wings tawny instead 

 of pure white. In Nicaragua, however, and further to the southward speci- 

 mens approach more nearly to the race prevalent in the north-western i>ortions 

 of the southern continent [megalippc'], and have these spots white and the veins 

 of both wings more strongly margined with black. These characters are very 

 slight, and show a tendency to a certain type rather than a present existing 

 definable feature; and therefore we are unwilling to separate them. Still the 

 di\ergence seems to commence in Nicaragua, all specimens found to the north- 

 ward belonging to the northern form [plejyii)pus'\, whilst those to the southward 

 generally, but not universally, belong to the southern [megriUjype]. 



Dr. Marston Bates wrote that "Cuban specimens of this species 

 * * * fall within the range of variation shown by the North 

 American population. Specimens from other West Indian islands 

 and from the tropical mainland have been separated as distinct choro- 

 morphs." He also said that "The apex of the forewing above is 

 almost entirely black in some specimens, and includes several white 

 spots ; the black border of the outer margin of both wings also includes 

 two rows of white spots, sometimes only partly developed." 



From this it would appear that both plexippiis and megalippe, 

 with intergrades, occur in Cuba as well as in parts of Mexico, south- 

 ern Central America, and along the southern and southeastern coasts 

 of the United States. 



Migration notes. — Our knowledge of the migrations of this butter- 

 fly is as yet very imperfect. We need man}^ more detailed records 

 than are available at present, especially in the southeastern portion 

 of the country, and we need far more information regarding the 

 assumed northward migration in the spring. 



The occurrence of a definite northward migration has always 

 seemed to me debatable. It appeared to me more likely that a few 

 individuals succeeded in overwintering in the north and that the 

 northern population was maintained year after year by these rather 



