PREFACE. 



rhis bulletin is the first of a series of cataloj^iies of type-speci- 

 mens of rooont animals which the U. S. National Museum intends to 

 publish as rapidly as circumstances will permit. The desirability of 

 formally designatino- a particular specimen to represent a species or 

 subspecies is an idea of comparatively recent origin; and although it 

 has gained general acceptance among zoologists, there are still some 

 who doubt its importance. Though there are perhaps some valid 

 arguments against the practice on theoretical grounds, there can be 

 no doubt that it puts an end to uncertainties with which earlier s3's- 

 tematists were often confronted. 



The practice was not in vogue generally when the National Museum 

 was established, and many speciuK'ns which according to present views 

 ought to have been speciall}^ treasured were not cared for more than 

 others, while the methods of preparing skins of mannnals were at the 

 same time very ci'ude. It has resulted from these circumstances that 

 the t3q)e-specimens of species described many 3'ears ago are not in as 

 good condition as they should be. Considering the earlier point of 

 view, howevei'. and the vicissitudes through which the collections have 

 passed in the course of a half century, it is fortunate, I think, that the 

 type-specimens have not fared woi'se. The t3'pe-specimens of the 

 more recenth' described species of mannnals, both in the regular series 

 and in the collection of the Biological Surve3% are with few exceptions 

 perfect or nearly so and very accurately and thoroughly labeled. 



The National Museum has in recent years fostered the depositing of 

 type-specimens of species of animals of all classes, and in this has had 

 the hearty cooperation of numerous American zoologists who con- 

 sider it a mattei" of importance to have these standards, as they may 

 be called, permanently preserved in the national (,'ollection. 



Frederick W. True, 

 Head Curator Departtiunt of Biol<)</ij. 



