296 CALIFORNIA ACADEMY OF SCIENCES [Proc. 4th See. 



it will be found that though the latter is in warmer waters 

 than the Galapagos and much nearer the mainland, the insect 

 fauna of this little island although quite meager, is of a dis- 

 tinctly more tropical aspect. The island is covered with good- 

 sized trees festooned with vines, and apparently possesses a few 

 clear areas. The climate is warm, the atmosphere heavy, and 

 there is water everywhere in the form of creeks and cascades, 

 but dense forests do not support a rich insect fauna. Only 

 two species of butterflies were taken on Cocos Island, and 

 neither of them occur in the Galapagos. One is an Aganisthos 

 (probably odius), the other is a species of delicate build which 

 has not yet been determined. Two Sphinges were seen there, 

 one the wide-spread Phleg. cingulata, the other which was not 

 taken, suggested the large Pachylia iicus. 



The butterflies of the Galapagos Archipelago number six 

 species, two of which were taken for the first time on this 

 expedition. These latter species are Pyrameis hunt era and 

 carycB. Both are rare in the islands. The Sphingidce number 

 eight, two, Triptogon lugubris and Theretra tersa, are here 

 reported for the first time from the islands, the former species 

 being plentiful, the latter rare. 



RHOPALOCERA 



Callidryas eubule, Linn. 



Agraulis vanillse, Linn. var. Galapagensis, Holland. 



Pyrameis huntera, Fabr. 



Pyrameis caryse, Hubner. 



Cupido parrhasioides, Wallengren. 



Eudamus galapagensis, N. Sp. (Williams). 



PIERIDAE 



1. Callidryas eubule Linn. Syst. Nat., p. 743, 1766. Hol- 

 land. Proc. U. S. N. M., XII, 195, 1889. 



Holland (Proc. U. S. N. M., XII, 195, 1889), says: "Dif- 

 fers in no respect from the forms taken commonly in the 

 Southern United States and West Indies." The Galapagos 

 specimens are certainly more referable to the form senncB as 

 described by William H. Edwards (Trans. Am. Ent. Soc. IX, 

 9, 1881), being "generally smaller than eubule/' the 9 having 



