UNIVERSITY OF CALIFORNIA PUBLICATIONS 



BULLETIN OF THE DEPARTMENT OF 



GEOLOGY 



Vol. 10, No. 12, pp. 179-183 Issued March 23, 1917 



SYSTEMATIC POSITION OF SEVERAL 

 AMERICAN TERTIARY LAGOMORPHS 



BY 



LEE RAYMOND DICE 



CONTENTS 



Introduction 



Archaeolagus, new genus 



Hypolagus, new genus 



Oieolagus, new genus 



INTRODUCTION 



A study of the teeth of many lagomorphs, including both Recent 

 and extinct forms, has shown that the enamel patterns furnish re- 

 markably constant diagnostic characters. Each species commonly 

 possesses a distinct tooth pattern and there are usually striking dif- 

 ferences separating the genera. The most important characters are 

 the number and form of the re-entrant angles of P s , the number of 

 re-entrant angles of P-, and the depth and amount of crenation of the 

 re-entrant angles of the upper molariform teeth. 



Until a few years ago nearly all the Leporidae were included in 

 the genus' Lepus, but more recently the family has been divided into 

 a number of distinct genera. A critical study of two fossil species 

 previously placed in the genus Lepus shows that they cannot be re- 

 tained in 'that' genus as it is now restricted, and new genera- are there- 

 fore proposed for their reception:- 



" Another species of lagomorph previously referred to Palaeolagus 

 is shown by the characters of the enamel patterns to belong to the 

 family Oehotonidae, but it differs from any known form in that family, 

 and for it also a new generic name is proposed. 



