242 Palmer — Generic and Family Names of Rodents. 



intended to include all the species, living and extinct, now recog- 

 nized. Even with these aids the student will often find difficulty 

 in looking up synon3any or determining the earliest name of a 

 genus, for Thomas gives only about one-third of the names, while 

 Trouessart does not pretend to include all the generic synonyms 

 and frequently omits references. 



The present paper differs from either of those just mentioned. 

 It is neither an index nor a catalogue of recognized genera, but 

 merely an attempt to bring together nil the names, generic and 

 subgeneric, ever pro])Osedi It is not complete in itself, inasmuch 

 as it gives neither references to descriptions nor localities ; but 

 the authority, date of publication, and type or included species 

 under each name will throw some light on these points. In ar- 

 ranging this list everything has been subordinated to convenience 

 of reference. Genera and subgenera have been treated alike and 

 distributed under families, while the alphabetical arrangement has 

 been followed both in the sequence of higher groups and in the 

 names under each family. Some difficult}^ has been experienced 

 in properly grouping the genera, and about a dozen names have 

 not been referred to any family for lack of sufficient information' 

 regarding their status. Thomas' classification of recent genera 

 has been followed, except in the case of Lophiomijidx, which is 

 given full family rank, instead of being placed as a subfamily 

 under Muridx. To these 22 groups have been added 5 additional 

 families of extinct rodents recognized by Zittel,' making a total 

 of 27 families. More than 200 names occur under Muridse, and 

 for simplicity they have been placed under subfamilies, but this 

 is the only instance in which the alphabetical arrangement of 

 the family has not been followed.'' 



The date is always the year of actual iiuhrication, often very 

 different from the date of apparent puljUcation. For exam[)le, 

 the description of Schizo don was published in the Proceedings of 

 the Zoological Society of London for 1841, but it did not actually 

 appear until March, 1842. Arctomys was described in a part of 

 the fourth volume of Schreber's Saugthiere, issued in 1782, but 

 the name was first published on plates accompanying this work, 

 which are known to have been distributed in 1780. Schizodon 



1 ' Handbuch der PaUeontologie,' IV, 1892-'93. 



^I am iiide1)ted to Mr. Thomas for looking over the genera of Mnridx 

 and Octodontidw and for several suggestions as to the arrangement of the 

 list. 



