1874.] 305 [Ridgway. 



various local naturalists ; but the long-settled and easily-accessible 

 district here treated, has, to the present day, been neglected. 



In his valuable work on the geographical distribution of North 

 American birds 1 Mr. Allen notes in the following words the lack of 

 information in regard to the avifauna of the region of which the lower 

 Wabash Valley is a part: — "The data are tolerably full only for 

 the region embraced between the St. Lawrence and the Upper Lakes 

 on the north, and the Ohio River and Virginia on the south. Much 

 is also known, however, in regard to the other Atlantic States; but 

 in respect to the whole region of the lower Mississippi and the Gulf 

 States, the recorded facts bearing upon this subject are lamentably few. 

 The importance of complete and carefully annotated lists of the 

 birds of many localities in the South Atlantic and Gulf States, and 

 in the Mississippi Valley, is hence clearly manifest" (p. 391, italics 

 are ours.) Although the lower Wabash Valley does not appar- 

 ently come within the region indicated above in a geographical sense, 

 yet it is demonstrable that it is strictly a part of it as far as its natu- 

 ral productions are concerned. 



The field of this paper comprises the area drained by the Wabash 

 River and its tributaries, both in Illinois and in Indiana, as far north 

 as Vincennes, and lies between parallels 38° and 39° North latitude. 

 The greater part of the investigations upon which it is based have, 

 however, been made in the vicinity of Mt. Carmel (Wabash County) 

 and Olney (Richland County) in Illinois, and on the Indiana side of 

 the Wabash River directly opposite the former locality. Occasional 

 excursions to the southward not having revealed the slightest differ- 

 ence in the avifauna from that of the three points mentioned, it is 

 presumed that its character is quite homogeneous throughout the 

 whole extent of the district named. In fact, though the distance 

 from the Ohio River to the nearest point on the Gulf of Mexico 

 is fully six hundred miles, no very marked change can be noticed 

 in either the fauna or flora in proceeding southward along the Missis- 

 sippi, until the alligator (A . mississijjpiensis), long moss (Tillandsia 

 usneoides), evergreen magnolia (M: grandiff.ora), live oak (Quercus 

 virens) and fan-palm (Chamcerops) are first found, at a certain lati- 

 tude (somewhere near the parallel of 33°), which marks the northern 

 limit of the sub-tropical belt of the Gulf coast. Of course the char- 

 acteristic southern species gradually become more abundant to the 



i Bulletin of the Museum of Comparative Zoology, Cambridge, Mass., Vol. n, 

 No. 3, pp. 375-425, 1870. 



PROCEEDINGS B. S. N. H. — VOL. XVI. 20 JUKE, 1874. 



