186 



the Carolinian fauna will be about the same, but the exact figures cannot 

 as yet be given. To the Carolinian fauna belong also the great majority 

 of the other forms of animal life in the State. 



As some members of the Academy may not be acquainted with Dr. 

 Merriam's paper I would state that he divides the continent of America, 

 according to the distribution of its animals and plants, into three primary 

 transcontinental regions, viz., Boreal, Austral and Tropical. The Boreal 

 region covers the whole of the northern part of the continent from the 

 Polar sea southward to near the northern boundary of the United States. 

 and occupies also the higher parts of the three great mountain systems, 

 viz., the Sierra-Cascade range, the Rocky and the Alleghany mountains. 



The Tropical region is represented in the southern part of the penin- 

 sula of Florida only. The Austral occupies the intervening territory, cov- 

 ering the whole of the United States and Mexico except the Boreal moun- 

 tains and Tropical lowlands. 



Bach of these three great regions is again subdivided into a number 

 of minor belts or areas, known as zones, and characterized by particular 

 associations of animals and plants, the Austral region, which alone is 

 represented in Indiana, being subdivided into the three transcontinental 

 belts mentioned above, namely, the "Transition," "Upper Austral" and 

 "Lower Austral" zones. 



THE TRANSITION ZONE. 

 The uppermost of the three Austral divisions is the transcontinental 

 belt in which the Boreal and Austral elements overlap. In Indiana it is 

 represented in the two northern tiers of counties, which counties embrace 

 several hundred fresh water lakes within their bounds. These lakes range 

 in size from an area of half an acre up to five and a half square miles. 

 About their margins are often extensive areas of low boggy land covered 

 with numerous forms of plant life whose main distribution is far to the 

 north and which have here their southern limit. Among the more charac- 

 teristic plants of the Alleghanian flora, which are found only in the north- 

 ern fourth of Indiana, are the following : Larch or tamarack, Lwrix lari- 

 cina (Du Roi) ; arbor vitae or white cedar, Thuja occidentalis L.; false 

 lily of the valley, Unifolium canadense (Desf.) ; moccasin flower, Cypri- 

 pedium acaule Ait.; showy lady's slipper, Cypripedium reginae Walt.; 

 bog orchis, Arethusa bitlbosa L. ; fen orchis, Leptorchis loeselii (L.) ; sweet 

 fern, Comptonia peregrina (L.) ; paper or canoe birch, Betula papyrifera 

 Marsh; speckled or hoary alder, Alnus incana (L.) ; gold-thread, Coptis tri- 



