SCIUEID^E— SCIUEES CAEOLINENSIS AND VARIETIES. 707 



considered as the vicinity of the Potomac River on the Atlantic coast. 

 Probably var. leucotis occurs southward in the mountains to Georgia, while 

 again, in the Mississippi Valley, the southern boundary of its habitat sweeps 

 northward as far as Southern Illinois. Along the Atlantic coast, no melanistic 

 phase of var. carolinensis has as yet been reported, but in Louisiana and 

 northward along the Mississippi a melanistic phase has been said to occur, 

 forming the S. fuliginosus of Bachman. 



Geographical distribution — The present species ranges eastward 

 along the Atlantic coast to New Brunswick, and is found thence westward 

 over the southern half of Maine, most parts of Vermont, New Hampshire, 

 and New York, most of the Saint Lawrence Valley, the southern portions of 

 Canada, Michigan,* Wisconsin, Iowa, and up the Missouri, at least to the 

 mouth of the Platte, and thence everywhere southward to the Gulf coast. 

 It ranges westward to the eastern border of the Plains, from Nebraska to 

 Texas, and apparently far into Mexico. Its northern limit of distribution 

 coincides very nearly witli the northern boundary of the Alleghanian fauna, 

 and hence very nearly with the isotherm of 44° F. Variety leucotis may be 

 considered as ranging southward over both the Alleghanian and Carolinian 

 faunae, or about to the isotherm of 56° F., where wars, leucotis and carolinensis 

 become not readily distinguishable. Var. carolinensis occupies the region 

 thence southward, in the United States, to the Gulf coast, and also far into 

 Mexico, and even apparently to Guatemala. 



In the United States, it has not been reported from any locality west of 

 the eastern edge of the Plains or west of Texas. The specimens from New 

 Leon, Mexico, are the most southern I have seen, and depart somewhat from 

 any of the forms met with in the United States. The descriptions of 8. 

 carolinensis, from Mexican specimens, seem unquestionably referable to this 

 species, and seem to indicate that the form met with in Central and Southern 

 Mexico is not greatly different from the form occurring in the middle portions 

 of the United States, though referred to as smaller and more fulvous. 



The form I have characterized above as var. yucatanensis is possibly 

 specifically distinct, but, if so, has very close affinities with the New Leon 

 type of S. carolinensis. The four specimens of this form in the collection 

 are all from Merida, Yucatan. I have met with no description that is at all 

 referable to this form, and can hence add nothing further respecting its range. 



* Richardson refers to the occurrence of the black form on the northern shores of Lakes Huron and 

 Superior, and gives its range as extending northward to the fiftieth parallel. — (Faun. Bor.-Amtr. vol. i, 

 1823, p. 191.) 



