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MURIDAE— BIGMODONTE8— HE8PEKOMY8 LI5UC0PUS. 

 Taiilk X\.—Me<uurtmmU oftieeltt ipudmcm purporting to he Hk8PKROMY8 "AiTBTenus". 



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*T' la apflolniMi la remarkftbly blacklah, with Tory pnra white fe«t, Mid aeon by Itaelf would readily sofupat a 

 dlatlnctlon of apectee from ordinary Uu$oput. It Is the extremo of tbo "anaterua " atyle. 



This little table is curious and suggestive. The twelve specimens hnppf^n 

 to differ among themselves in size and proportions nearly as much as the 

 whole eastern series of leucopus does, and show more variation than would 

 be required to establish several distinct species upon the slight basis that has 

 been often employed. And after allowing a wide margin for chances of error 

 in measurement (always a safe thing to do in dealing with stuffed skins of 

 small mammals), discrepancies remain that cannot be explained away. The tail 

 varies an inch, and the ears and feet are quite as variable. To sum up (with 

 special reference to "boylii", thot we are about to diticuss) : The tail, com- 

 pared with the trunk, ranges from less than the average of eastern leucopus 

 up to nea;ly the average of "myoides" or "boylii". The ears range from the 

 smallest of leucopus to the largest of "boylii". The feet have the ordinary 

 range of either leucopus or "boylii". Nothing further is needed to prove our 

 point. 



In analyzing out species of Hesperomys, Professor Baird put "myoides" 

 and "boylii ' together, because they agreed in a length of tail exceeding the 

 average of tiuo leucopus. Of "boylii" he says : — "No cheek-pouches ! Tail 

 three-quarters o( an inch longer than the [head and] body"; and of "myo- 

 ides": — "With cheek-pouches. Tail a quarter of an inch longer than the head 

 and body." The supposed distinctions of color do not hold ; for No. 1313 

 (" myoides", Burlington, Vt.) and No. 578 (" boylii", Shoalwater Bay) are almost 

 precisely alike in color — much more so than two specimens of "boylii'' (No. 

 678 and No. 356, for example) are. No. 356, the type of "boylii", is the very 



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