304 ENTOMOLOGY 



the preglacial fauna. "The glacial cold still lingers over the northern 

 part of this continent and our present animals are only a remnant of 

 the rich fauna that existed in former ages, when the magnolia and the 

 sassafras thrived in Greenland." 



Island Faunae. The ability of insects to surmount barriers, under 

 favorable circumstances, is strikingly shown in the colonization of oceanic 

 islands. Not a few insects, including Vanessa cardui, have found their 

 way to the isolated island of St. Helena. In the Madeira Islands, ac- 

 cording to Wollaston, there are 580 species of Coleoptera, of which 314 

 are known to occur in Europe, while all the rest are closely allied to 

 European forms. Subtracting 120 species as having been introduced 

 probably or possibly through the agency of man, there remain 194 that 

 have been introduced by "natural" means. The rest, 266 species, are 

 endemic, though akin to European species. 



The scanty insect fauna of the Galapagos Isands includes twenty 

 species of Orthoptera, which have been studied by Scudder and by Snod- 

 grass. Five of these are cosmopolitan cockroaches, doubtless introduced 

 commercially, and the remaining fifteen are all "distinctly South and 

 Central American in their affinities. " Three of these fifteen are strong- 

 winged species which doubtless arrived by flight from the neighboring 

 mainland; indeed, Scudder records a Schistocerca (S. exsul) as having 

 been taken at sea two hundred miles off the west coast of South America, 

 or nearly half way to the Galapagos Islands. Thirteen of the fifteen 

 are endemic, and five are apterous or subapterous, while a sixth has an 

 apterous female. Apterous insects, noticeably common on wind-swept 

 oceanic islands, may have been carried thither on driftwood, though it 

 is more likely that the apterous condition arose on the islands, where the 

 better-winged and more venturesome individuals may have been con- 

 stantly swept out to sea and drowned, leaving the more feeble-winged 

 and less venturesome individuals behind, to reproduce their own life- 

 saving peculiarities. 



The Coleoptera of the Hawaiian Islands, studied by Dr. Sharp, num- 

 ber 428 species, representing 38 families, and "are mostly small or very 

 minute insects," the few large forms being non-endemic, with little or 

 no doubt; 352 species are at present known only from this archipelago. 

 Dr. Sharp distinguishes three elements in the fauna: "First, species that 

 have been introduced, in all probability comparatively recently, by arti- 

 ficial means, such as with provisions, stores, building timber, ballast, or 

 growing plants ; many of these species are nearly cosmopolitan. Second, 

 species that have arrived in the islands, and have become more or less 



