4 BULLETIN 17 8, UNITED STATES NATIONAL MUSEUM 



Since a single type sometimes has more than one number, a few 

 words about the cataloging of these specimens seem desirable. In the 

 records of the National Museum two systems of cataloging have been 

 used : First, a "double entry" system, in which all the skulls were en- 

 tered in one catalog and all skins and alcoholic specimens in another. 

 The complete number of a specimen so cataloged is indicated by a 

 fraction; thus. No. ^-^-||- on a skin means skin No. 1163, to which 

 belongs slaill No. 2045 ; while ff|f on a skull means skull No. 2045, to 

 which belongs skin No. 1163. At the suggestion of Frank H. Hitch- 

 cock, then a clerk in the Biological Survey, this cumbersome method 

 was abandoned at the end of the year 1892 in favor of a "single entry" 

 system in which each individual is given one number regardless of 

 whether it is preserved as a skin, skull, skeleton, or alcoholic specimen. 

 The new system began with No. 50001 in January 1893. Since that 

 date there have been no separate entries for skins and skulls, one 

 number being used for each entire specimen. 



The type specimens have been taken out of the regular study col- 

 lections and placed in separate storage cases plainly labeled on the 

 outside "Types," where they receive special care and attention. 



SUMMARY OF THE LIST OF TYPES 



The present catalog includes types, cotypes, lectotypes, and chiro- 

 types, as defined by Thomas (Proc. Zool. Soc. London, 1893, p. 241) 

 and Schuchert (U. S. Nat. Mus. Bull. 53, pt. 1, p. 7, 1895) . Appended 

 to the catalog of type specimens now actually in the two collections 

 is a list of those, 21 in number, that should be in these collections, but 

 are now apparently lost or destroyed (p. 571). The number of types, 

 cotypes, lectotypes, or chirotypes in each of the families represented m 

 the two collections is shown in table 1. 



EXPLANATION OF SYMBOLS 



A dagger (t) is placed before the scientific name of a type in the 

 Biological Surveys collection. An asterisk (*) indicates that the 

 specimen is in the National Museum collection. 



