ECOLOGY OF ISLE ROYALE. 181 



ington, D. C] by the change of seasons, so in early spring we may always expect 

 more northern types, while in midsummer the southern ones predominate." 



VanDyke. E. J. 190i: pp. 198-199. 



"The California faunal region proper includes practically all the lowlands of 

 the State, the fertile valleys of southern California and the extensive valleys of 

 the San Joaquin and Sacramento, the lesser valleys along the coast and the foot 

 hills bordering them. The fauna prevailing throughout these portions are so 

 affiliated with Sonoran forms, particularly toward the south as to warrant the 

 designation of such portions as Sonoran sub-regions, and by the extension of 

 these forms into the foot hills where they have interbred with Boreal types 

 through a series of ages, genera characteristic of both parent regions have been 

 evolved. Omus, Brennus (a cychrid subgenus). Metrius. Promecognathus, Pleo- 

 coma, and Rosalia with others while more or less related to adjacent northern 

 forms probably developed .from a rich circumpolar fauna under the influence of 

 adaptation to environment. Omus occurs rather generally throughout the state, 

 and Metrius and Promecognathus similarly but less frequently in the moist timber 

 belt of the Coast Range, although an Alpine variety of Metrius is found in the 

 Sierras, and Brennus is confined to the coast. Many other examples of restricted 

 location could be given. In earlier periods California was more isolated partic- 

 ularly from the Sonoran region and northern influences prevailed. Then such 

 genera as Omus and Plecoma became first established. Subsequently a few south- 

 ern forms such as Coniontis and its congeners gained access. These constituted 

 the old California fauna, but when the southern isolation ceased, followed by the 

 invasion of Sonoran forms, a new and later fauna was developed. This theory 

 is partially supported by the fact that in the islands off the coast and in certain 

 still isolated areas are faunas which are largely sui generis, and typical of the old 

 California fauna above described." 



Wickham, H. F. 1902. pp. 221-222. 



"The phenomena of distribution in Colorado are of much interest. Within a 

 radius of a few miles we may find assemblages of species representing at least 

 three distinct faunae. The first, that of the great plains surrounding the moun- 

 tains, is marked by a great development of wingless or imperfectly winged forms, 

 probably largely , Invaders from the south where we may suppose that the arid 

 deserts first made their appearance and where this characteristic feature is more 

 in evidence among the beetles. Good examples may be found among the Meloidae. 

 Tenebrionidae and epigaeal Rhynohophora. Occasionally these forms leave their 

 natural haunts and extend for long distances up the river valleys. Thus Eleodes 

 may sometimes be met with at altitudes exceeding ten thousand feet. As we enter 

 the timbered country on the higher foot-hills and lower mountain sides, we en- 

 counter a fauna which while not unmixed with species that ha,ve come up from 

 the plains, shows a strong affinity to the life about our Great Lakes. Higher still 

 — that is to say from about eight thousand to nine thousand feet, according to 

 the exposure, presence or absence of near-by snow-fields and so on — we meet with 

 many species of genera still more boreal In habits. We may mention Nebria with 

 its many species, usually taken along the coldest mountain streams, the flattened 

 Bembidia, and the large Aphodii. Above timber line the peaks susWn a few 

 beetles which seem to be of arctic origin, left, probably, by the retreating ice- 

 sheets of the Glacial period. 



"I cannot agree with Prof. Cockerell* who claims that the Glacial epoch would, 

 for the time being result in the almost complete extermination of the .insect fauna 

 of Colorado and the adjacent table-lands. He assumes that the arid region 

 'where not actually glaciated would be a frozen desert,' something which I think 

 is not indicated by such geological evidence as we possess. The glaciation of Col- 

 orado was apparently not particularly extensive. Neither does it seem likely that 

 the western ice-sheet went so far south as San Diego; at any rate the indications 

 seem to show that along the highlands of Southern California only the loftier 

 mountains were glaciated at all. Today great glaciers exist in the immediate 

 vicinity of well-wooded districts rich in animal life. The same phenomenon may 

 have occurred during ancient times." 



1893. pp. 232-233. 



" 1. That the fauna of southern Alaska is less closely related to our alpine, 

 northern Inland, or north-east coast faunae than is that of the Stikine Canon or of 

 Glenora. 



'* Transactions of the American Entomological Society, Vol. XX, p. 319. 

 24 



