8CIUKI1)^^-8(1IU1{UH NKIKU AND VAIUKTIHS. 



23 



northern. Judged hy tliis stnndard, the specimens from Snint Louis, Mo., 

 must be regarded ns fully as large us tliose from further north, if not, indeed, 

 a little larger. 



The geographical vuriation in color in vnr. iudovicianu.i consists, ns 

 already noticed, in an increasing pallor northward and toward the dryer ]Hir- 

 lions of the plains, and, in the country immediately bordering the Missis- 

 sippi, in a strongly marked increase in color southward. 



Geoorapiiical DI8TBIHUTI0N. — Vurs. citwreus und niger occupy the Atlan- 

 tic slope from New York southward, var. niger being found westward in the 

 Gulf States 08 far as Eastern Louisiana. Var. cinereus has been report(>d us 

 common on Long Island, and- as occurring as fur eastward as Massachusetts, 

 but, if ever found in the last-named locality, can occur there only very rarely. 

 Both var. cinereus and var. niger occur in Maryland ond Virginia, where their 

 habitats overlap, and the two forms interblend. Probably vnr. cinereus ranges 

 farther southward along the mountains of the interior than along the coast. 

 Var. ludovicianus appears to occupy nearl" the wliole region drained by tlic 

 Mississippi and its eastern tributaries, and extends up the Missouri to above 

 Fort Randall, and occurs along the Arkansos, the Red, and the other princi- 

 pal rivers that come down from the Plains as far as they are regularly bor- 

 dered with timber. The westernmost localities represented by the specimens 

 before me are the Republican Fork and the vicinity of Fort Cobb, Indian 

 Territory. It is found throughout a large part of Texas, and doubtless 

 ranges far into Mexico. It has even been reported as occurring as far south 

 ns Guatemala,* but I think the identification in all probability erroneous. 



Synonymy and nouenclature. — The earliest available name for the 

 (specific designation of the Fox Squirrels is doubtless niger, used by Catesby 

 in 1743, and adop' y Linnaeus in the tenth edition of the Systema Naturte 

 (1758), based on tbc Large Black Squirrel of Catesby, which unquestionably 

 refers to the dark phase of the Southern Fox Squirrel. Immediately follow- 

 ing it, on the same page of this edition, is the name cinereus, generally con- 

 sidered as referring to the Northern Fox Squirrel, the Cat Squirrel of Bachman. 

 Tlie only objection to niger as applicable to the whole group is that it refers to 

 only a single phase of coloration, and not to the most prevalent one, though 

 a very common one. In view of the great frequency of the black and dusky 

 phases of coloration, the objection is one of no great importance, and I hence 



• Toniea, Ptoo. ZoOl. Soo. Lond. 16C1, p. 8»1. 



