SS| 



RIONOOKAPIIS OF NORTH AMERICAN RODENT! A. 



introduction and increase in New Jersey are given mainly on the authority 

 <»!' Mr. Jillson, and are fully covered by Mr. Jillson's later and more detailed 

 account already quoted. 



From the foregoing, it will be seen that from the single pair introduced 

 accidentally to the fields about Tuckerton in 1867 — only ten years ago — the 

 species has spread over a belt of country some thirteen miles in length and 

 probably several miles in breadth, and that its numbers already render it a 

 farm pest, which evidently cannot be soon, if ever, wholly eradicated. It 

 shows, furthermore, that the species is capable of multiplying in a region 

 quite different from its original habitat. Whether the changed conditions 

 will ultimately modify materially its habits and structure remains an inter- 

 esting question for later investigators. 



TABLE CXXIV — Measurements of seven skulls of Spermopiiilus franklini. 



Table CXXV. — Measurements of twelve specimens of Spkkmophilus franklini. 



11592 

 11593 



1I5SG 

 11597 

 11601 

 11602 



■'.m 



•911 

 •949 

 '3762 

 •3761 

 •3019 



Fioui tip of nose to — 



Locality. 



Pembina, D. T 

 do 



..do . 

 ..do . 

 ..do. 



do 



Liwn Ridge, "1 

 do 



Peoria, III 



Minnesota 



do 



Cook County, III 



Tail to end 

 of— 



Length of— 



W 



0.93 

 0.90 

 1.00 

 0.95 

 1.10 

 1.U0 

 0.98 

 0.95 

 0.98 

 0.93 

 0.95 

 1.00 



W 



2.17 

 1.80 

 2.00 

 ','. 50 

 1.00 

 2.00 

 1.80 

 1. 75 

 1.85 

 1.78 

 1.90 

 1.87 



6.25 

 5.00 

 5.00 

 7.00 

 5.00 

 =..50 

 4.40 

 4.85 

 4.55 

 4.35 



4.75 



H 



7.45 

 6.25 

 6.60 

 8.50 

 6.50 

 7.00 

 6.30 

 5.00 

 6. 00 

 5.80 



0. 23 



1.35 

 1.37 



1. bt) 



1.35 

 1.35 

 1.40 

 1.27 

 1.45 

 1.25 

 1.10 

 1.15 

 1.37 



1.90 

 1.95 

 1.90 

 2.00 

 2.00 

 2.00 

 1.97 

 2. 12 

 2.05 

 1.90 

 2.00 

 2.07 



0.35 

 32 

 0.27 

 0.27 

 0.32 

 0.35 



Fresh. 

 ... do. 

 ...do. 



..do. 

 ... do. 

 ...do. 

 Alcoholic- 

 ....do. 

 ....do. 

 ....do. 

 ....do. 



...do. 



• In Museum of Comparative Zoology, Cambridge, Mass. 



