DR. w. w. Ely's notes on chapter ii. 203 



that of older specimens. The form of these bones, i.e. their 

 width and convex outer margin, differ much in American speci- 

 mens. Having examined this subject with much care, Brandt 

 concludes in respect to the nasal bones, that there remains "only 

 their more considerable length in comparison with the skull as 

 a mark of the European heaver.''^ 



I have carefully examined over one hundred skulls in reference 

 to this point, the measurements being made with callipers, the 

 length being estimated from the inferior border of the intermax- 

 illary to the occipital crest in the median line. 



In six American skulls the average length is b" 39'"^. The 

 average length of the nasals is \" 80'"|, an excess of 13'^'^ 

 over one-third the length of the skull. 



In three skulls having an average length of 4" 42'", the 

 length of the nasals is \" 58'"|, making the excess over one- 

 third 34'". 



In seven skulls whose length respectively is b" 10'", 3" 95"', 

 5" 10"', 5" 13"', 4" 94'", 5" 13'", 5" 17"', the excess of 

 length of the nasals over one-third the length of the skull is 63'", 

 34"', 30'", 42'", 46"', 51'", 47"'. 



In the New York skull. No. 1U72, in which the backward pro- 

 iection of the nasals resembles some of the European skulls, the 

 excess over one-third is but 11'". In the European skull, No. 6564, 

 in which the backward projection of the nasals appears to have its 

 maximum, this excess is 29"', which is much less than in many 

 American skulls. We must conclude, therefore, that the back- 

 ward projection of the nasals, and their greater proportionate 

 length as compared with American skulls, are not constant and 

 distinctive features of the European variety. 



"5. The frontal portion of the lachrymal bone of the American 

 beaver is more triangular, posteriorly twice as broad as ante- 

 riorly, and smaller than in the European ; it is also nearly limited 

 to the space between the malar and frontal bones ; since it im- 

 pinges onl}"- with its anterior border-like narrow end upon a small 

 process of the upper jaw, or even only approaches it. In the 

 beavers of the Old World, however, the larger, more quadrangu- 

 lar, anteriorly and posteriorly equally broad frontal portion of the 

 lachrymal bone lies not only between the malar and frontal bones, 

 but is united in similar extent equilaterally with the superior 

 maxillary." 



