[36] 



mate elevation of 2,500 feet,* and at the northern Hmit of Vir- 

 ginia about three degrees to the northward (allowing as a rough 

 estimate a diminution of i°.5 to the degree of latitude and of one 

 degree of temperature for every three hundred feet of elevation, 

 which agrees pretty accurately with recorded temperature obser- 

 vations) corresponds to the elevation of i , 1 so feet, or at the lat- 

 itude of the extremity of the ''pan handle" of VVest Virginia a 

 degree farther north would answer to a licight of 700 feet. The 

 Virginian species ordinarily limited in tiieir northward range by 

 this fauna are Cardinalls cardinalis^ Spiza anicricana^ Giiiraca 

 ccerulea^ Hehnitherus verm Ivor us, Ictcria virciis, Protonota- 

 ria cit7'ca^ Sylvan ia mitrata, IJcndroica cocruleas Piranga 

 rubra,, ]\Jimus polyglottus,, Thryothortis hidovicianus,, Poliop- 

 tila ccerulea^i Lophophanes bicolor, C'orvus ossifragus, Ceniu- 

 rt4S caroliiius, Stelgldoptcrvx serripciinis, Strix Jiatiunea,, 

 Cathartcs aura^^PLgialitis zvilsonius, GaUhmlagalcata, lonor- 

 nis jnariinica^ Ardca candidissbna and Ardca ccerulea. Within 

 its limits are comprised the whole of Virginia east of the Blue 

 Ridge (including the lower parts of that mountain range), 

 except the portion belonging to the Louisianian fauna and prob- 

 ably the highest parts of some of the mountains of the Piedmont 

 region ; most of the Valley ( except the highest portions, espe- 

 cially the Massanutton mountain and the elevated south-western 

 section situated about the head waters of the Roanoke and Hol- 

 ston and upper part of the New Rivers) ; the less elevated valleys 

 of the mountain districts, and West Virginia between the moun- 

 tains and the Ohio river. West of the Blue Ridge and east of 

 the Alleghanies however the fauna is not so t3pically Carolinian 

 as in Eastern Virginia and in the Ohio valley. Between the 

 isotheral of 65° (which may be estimated as being found in the 

 Virginias according to latitude at the elevation of from about 

 2,900 to 4,300 feet,) and the line of 71° the fauna is Alleglianian 

 as shown bv the presence in the breeding season of Hclwinthoph- 

 ila chrysoptera, Enipidonax minim Jis^ Vireo solitarius alticola^ 

 Compsothlypis americana,, Con t opus borcalis, Dcndroica 

 pennsylvanica with doubtless several other species. The line 

 of demarcation between this and the preceding fauna is not, 



•Means summer temperature of Wytheville, Va. (elevation 2,24:.' ft.) 71° F, 



