CATALOG OF TYPE SPECIMENS OF MAMMALS ■ 6 



quent authors references to these are added. The current name is pre- 

 ceded by the sign of equality and followed by a citation of the au- 

 thority for its use. An author's name is placed in parentheses when 

 the generic name that he used in the original description has been 

 changed. 



The citations are followed by: (1) U. S. National Museum catalog 

 number. (2) Nature of specimen, whether skin and skull, or skull 

 only, or skin only, or skeleton, or specimen preserved in alcohol. (3) 

 Age and sex (omission of the sex indicates that it is not known). (4) 

 Locality. (5) Date of collecting (omission of date indicates that it is 

 not known). (G) Name of person by whom collected, or from whom 

 received, or from whom purchased if collector is not known. (7) Orig- 

 inal number of specimen, usually the number in the collector's field 

 catalog. Some Biological Survey original specimen numbers are fol- 

 lowed by the letter X. This indicates that the specimen is entered 

 in the "X Catalog" of the Fish and Wildlife Service, in which are 

 recorded specimens acquired by exchange or purchase or received 

 from or collected by persons other than members of the permanent 

 staff. (8) Date when specim.en was cataloged, when date of collec- 

 tion is unknown. (9) The condition of the specimen at the present 

 time is briefly stated. Skull conditions are graded as follows : 



Grade A=Skull showing all essential characters. 



Grade JS=Skull sufficiently defective to lack some essential characters. 



Grade (7= Skull lacking most of the essential characters. 



Grade D=Skull fragmentary. 



Examples of the four grades might be as follows : 



Grade A. — Complete, or lacking some unimportant part on one side only. 



Grade B — Lacking both zygoma s. 



Grade C — Lacking posterior or anterior portion of skull. 



Grade D — Nothing but fragments. 



Finally, the reasons are given for considering a particular specimen 

 as a type when it was not clearly so designated by the original author. 

 In the case of many early descriptions it is difficult to determine 

 whether any individual specimen formed the principal basis of the 

 description. In these cases, where no type was indicated by the writer, 

 preference has been given to specimens that have been figured or to the 

 ones that seem to be the most minutely described or measured among 

 those originally in hand. The views of subsequent writers have also 

 been considered in the selection of the type. In some cases it has 

 been found necessary to regard several specimens as cotypes of a species. 

 In a few cases the evidence for regarding particular specimens as 

 types is very unsatisfactory. Consequently a few of the specimens 

 here listed may not strictly be regarded as types in the present meaning 

 of the word. 



2.51o4;{— 42 2 



