Recent Litcrattire. 153 



former of these two has been extended northward on the coast to 

 latitude 38°, it having previously been considered as restricted to the 

 southern part of the State. Rubea has been left as before, as in- 

 habiting the Sacramento and probably the San Joaquin valleys, but 

 strigata, with the exception of the above mentioned islands, is not 

 ascribed to northern California even in winter, as it is in Ridgway's 

 Manual. 



The article concludes with a table of measurements and a map 

 showing the distribution of the different races. From the table we 

 learn how small is the value of measurements in determining the va- 

 rieties, there being far more difference in size between the sexes 

 than between many of the varieties. It is to be hoped that through 

 the instrumentality of the American Ornithologists' Union other 

 groups will be worked over in the same satisfactory manner. 



C* A. K- 



/ Some of the North 



of 



the Genus Taiuias. By J. A. Allen. Bull. Am. Mus. of Nat. 

 Hist., vol. iii, pp. 45-116. — In these days of radical and hasty hair- 

 splitting-, it is really refreshing to find a naturalist who looks twice 

 before creating new species which will soon help to crow'd the list of 

 synonyms. Probably no group of mammals offers so natural and 

 misleading an opportunity for forming new species as does the 

 genus Tamias; but Mr. Allen, in his admirable review of this group, 

 has not jumped at his conclusions, but has carefully considered the 

 subject from all its bearings. Owing to the extended range of this 

 genus and the exceedingly close relationship existing between the 

 species, a very large amount of material is necessary in order to 

 draw any conclusions of value; and although Mr. Allen had over six 

 hundred and fifty specimens at his command, he found even this 



number insufficient. 



The extren:icly important, or, indeed, vital problem of how to 

 distinguish specific or subspecific differences from mere individual 

 variation was presented to him in its most difficult form, and received 

 the careful attention it deserved. An examination of a series of 

 skulls demonstrated the very important fact that it was " impracti- 

 cable to make much use of cranial characters as a basis for specific 

 distinctions." This discovery is especially valuable, in view of the 

 fact that there has been a tendency of late to base nice specific dis- 



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