44 University of California Puhlications in Zoology [Vol. 13 



PAGE 



4. Diplodinium ecaudatum forma tricaudatum forma nova 92 



5. Diplodinium ecaudatum forma quadricaudatum forma nova 93 



6. Diplodinium ecaudatum forma cattanei 94 



7. Table of dimensions 95 



8. Observations on tlie living material 95 



D. Conclusions 101 



E. Addendum. Discussion of Braune's paper : 103 



F. Bibliography 110 



INTRODUCTION 



During the winter of 1909 Professor C. A. Kofoid, of the 

 University of California, called my attention to the papers of Fioren- 

 tini (1889) and Eberlein (1895) dealing with the protozoan fauna 

 of the stomachs of ruminants, and pointed out the fact that the life- 

 history of these protozoans had not yet been traced. This appealed 

 to me as an interesting bit of research, and acting upon Professor 

 Kofoid 's further suggestion I first made certain that material was 

 procurable and then consulted the literature upon the subject. The 

 papers of Schuberg (1888), Fiorentini (1889), Eberlein (1895), and 

 Giinther (1899, 1900), were at hand and from a hasty perusal of these 

 it became evident that the genus Diplodinium offered the greater pos- 

 sibilities as a research problem. Most of the described species of this 

 genus were present in the stomach fluid which I was able to obtain, and 

 especially abundant were the species which Fiorentini (1889) had 

 described as Diplodinium ecaudatum, D. caudatum, and D. cattanei. 



As my observations proceeded it became evident that the Protozoa 

 infecting the stomachs of western cattle presented many differences 

 in structure from those figured and described both by Fiorentini 

 (1889) and by Eberlein (1895). This was found to be especially true 

 in the case of those species described as belonging to the genus 

 Diplodinium. 



The present paper deals with the morphology of Diplodinium 

 ecaudatum Fiorentini including D. caudatum Fiorentini, and D. cat- 

 tanei Fiorentim, together with a description of three new forms of this 

 species, viz., Diplodinium ecaudatum forma bicaudatum, Diplodinium 

 ecaudatum forma tricaudatum, and Diplodinium ecaudatum forma 

 quadricaudatum, all of which are found in the first and second divisions 

 of the stomach of western cattle. 



