378 



Recejtt Literature. [October 



ican Fauna' (No. 3, Sept. 1890, and No. 5, Aug. 1891. See Auk, VIII, pp. 

 95-9S). In this paper he gives (after a few pages of introductory re- 

 marks) a general historical review of the subject (pp. 6-21), followed by 

 an extended discussion of the 'Life Regions and Zones of North America' 

 (pp. 21-38), and closing with an exposition of tlie 'Causes controlling 

 Distribution,' including 'Remarks respecting some of Wallace's Fallacies 

 (pp. 39-64). The historical synopsis of the proposed fauna! and floral 

 divisions of North America gives, in tabular form, the views of 56 differ- 

 ent writers on the subject, langing in date from 1817 to 1S91, of whom 31 

 were zoologists and 25 botanists. From this synopsis it appears "that a 

 number of zoologists and botanists, basing their studies on widely differ- 

 ent groups, and as a rule ignorant of the writings of their predecessors, 

 have agreed in the main in the recognition of at least seven (7) life areas 

 in extratropical North America, namely : (i) an Arctic area north of the 

 limit of tree growth ; (2) a Boreal transcofttiuejital coniferous forest 

 region; (3) an Atlantic or Easterti -wooded region, stretching westward 

 from the Atlantic to the Great Plains; (4) a Central or Middle regioii 

 reaching from the Plains to the Sierra Nevada and Cascade Mountains ; 

 (5) a Pacific or Californian division, covering the area between the east 

 base of the Sierra and the Pacific Ocean; (6) a Louisianian or Austrori- 

 farian division, comprising the South Atlantic and Gulf States south of 

 latitude 36'' ; (7) a Sonoratt division, occupying the high table land of 

 Mexico and stretching northward over the dry interior far enough to in- 

 clude the southern parts of California, Nevada, Arizona, New Mexico, 

 and Texas" (p. 21). In addition to this it has of late been the custom of 

 zoologists, or more particularly ornithologists, to subdivide the eastern 

 portion of North America into a series of lesser divisions or faunas, as (i) 

 the Arctic, (2) the Canadian, (3) the Alleghanian, (4) the Carolinian 

 (5) the Louisianian, and (6) the Fioridian. 



Dr. Merriam's investigations have led him to adopt a somewhat different 

 classification, which may be presented in tabular form somewhat as follows : 



I. Boreal Region. 



1. Arctic Divisioti. 



2. Boreal Cottiferous Forest Region. 



a. Hudsonian Zone. 



b. Canadian Zone. 



c. Timber-line Zone. 

 Neutral or Transition Zotte. 



II. SoNORAN Region. 



1. Upper Sonoran Zone. 



a. Humid Upper Sonoran. 



b. Arid Upper Sonoran. 



2. Loxver Sonoran Zone. 



a. Humid Lower Sonoran. 



b. Arid Lower Sonoran. 



III. Tropical Region. 



