170 MICHIGAN SURVEY, 1908. 



own district, and are -without any representatives in the other parts of the 

 country, pp. 249-250. 



"It must be observed that the localities east of the Sierra (Vallecitas, Colorado 

 and Gila) show more resemblance in their productions than the maritime regions 

 of California: the desert nature of the country undoubtedly produces this effect, 

 by presenting conditions unfavorable to animal life; yet even in this uniformly ' 

 sterile tract, great differences are observed among the smaller species which 

 abound only in moist places, p. 250. 



"The first point worthy of notice in this list is the extremely small number 

 [compared with Europe] of Soarabaei, Elateridae and Longicornia: this might 

 have been predicted, as these insects derive their food for the most part from 

 large plants. The Curculionidae and Chrysomelidae are not in the same pro- 

 portion as in the more wooded countries. The saprophagous Coleoptera, with 

 the exception of Histeridae, are almost wanting: and these latter are not in 

 larger proportion than with us. Thus the only effect, so far as observed, is 

 the paucity of species in tribes for which the country affords but little food. 

 The Staphylini and Carabica bear the same proportion to the whole, that they 

 do with us; while the deficiency caused by the small representation of the tribes 

 mentioned above, is made up almost entirely by the Tenebrionidae, which, as 

 is well known, are but slightly developed in Eastern America. The Malachidae 

 are also in larger proportion than in other parts of the continent." p. 251. 



"The Tenebrionidae, from being the group most characteristic of the country, 

 might be supposed capable of giving us the most certain data with regard 

 to the law of distribution. The great majority of the genera of this tribe are 

 apterous; and of those which are not apterous, all the genera found in Cali- 

 fornia are cosmopolitan (Phaleria, Platydema, Helops, Uloma, Tenebrio. Upis, 

 etc.), except Blapstinus, which again occurs in tropical America. Of the 

 apterous genera, only three are found in eastern temperate America: two of 

 these are peculiar, and one (Nosoderma) which exists in California is also 

 found in Brazil. Of this group, there are in California about 28 genera, of which 

 5 or 6 extend into the tropics. 



"The Histeridae, though not in undue proportion, exhibit a peculiarity: they 

 nearly all belong to the genus Saprinus, which, in Eastern America and Europe, 

 forms scarcely one-fourth of the group. 



"Thus the only manner in which the insect fauna of California approaches 

 that of Europe, is In the great abundance of apterous Tenebrionidae. But in 

 this respect it does not differ from a large part of South America and by 

 the very form of these Tenebrionidae, which bear no resemblance at all to those 

 of Europe, the greater relation of the Californian fauna to that of the rest 

 of America is clearly proved. It will be seen, too, that the resemblance to 

 European forms in the other tribes is only indirect, proceeding solely from 

 universal or zonal forms, while the greater relation is again with the rest 

 of America. It will moreover be seen, that while the stronger relation of the 

 fauna is continental, yet a sufficient number of Individual peculiarities are 

 introduced to prove that it constitutes a system of its own, bearing no relation 

 to that of Eastern America, except the slight continental resemblance proceeding 

 indirectly through the tropics, pp. 251-252. 



"The principles shown by the preceding analysis may be expressed briefly as 

 follows : 



1. California constitutes a peculiar zoological district, with sufficient relation 

 to the other districts of America to prove that it belongs to the same continental 

 system, 



2. This zoological district is divided into several sharply defined sub-districts, 

 having a very close resemblance to each other. 



As the same mode of distribution obtains in the group of islands adjacent 

 to the western coast of America, we are led to believe, 



3. That the local distribution of a small number of species is the characteristic 

 of the eastern Pacific region, as the extensive distribution of a large number 

 is the prevailing feature of the Atlantic. 



4. The genera occurring in, but not peculiar to, this district, belong to two 

 classes: either they occur on the Atlantic slope of both continents, or they 

 are peculiar to America, and are also found within the tropics." pp. 253-254. 



1859. pp. III-V. "Before proceeding to consider the special material used in the 

 preparation of this memoir, it will be proper to give a short sketch of the 



