NEMATODE PARASITES OF MAMMALS OF THE ORDERS 

 RODENTIA, LAGOMORPIIA, AXD HYRACOIDEA. 



By Maurice C. Hall, 



Assistant ZooUxjist, United <S7o/c.s' Bureau of Animal Industry. 



PREFACE. 



While engaged in the preparation of this paper the. writer has had 

 the great advantage of association with and criticism and assistance 

 from a number of eminent and competent workers. I take especial 

 pleasure in acknowledging the advice and the conservative and con- 

 structive criticism of Dr. Ch. Wardell Stiles. Among others should 

 be mentioned Dr. B. H. Ransom, the Chief of the Zoological Division 

 of the United States Bureau of Animal Industry, to whose policies 

 I am indebted for the opportunity to carry on this investigation in 

 connection with other work and whose previous study of the 

 nematodes of ruminants has served as a model. I am further in- 

 debted to Dr. Albert Hassall, assistant zoologist of the United 

 States Bureau of Animal Industr}^, for frequently assisting me in 

 the tracing of obscure references and for the numy nematodes of 

 rodents and rabbits which were available to me as a result of his 

 years of collecting. I am indebted to Miss Carrie Mj^ers, of the 

 Zoological Division of the United States Bureau of Animal Industry, 

 for the preparation of the bibliography and host list and for assist- 

 ance in the verification of numerous titles. For the selection of the 

 proper host names and the designation of s3^nonyms among host 

 names I am indebted to the courtesy of Mr. Gerrit S. Miller and Mr. 

 Xed Hollister, of the United States National Museum; while practi- 

 call}'^ all of the illustrations, originals or copies, were drawn by Mr. 

 W. S. D. Haines, artist of the United States Bureau of Animal In- 

 dustry. 



Outside of Washington, I am especially indebted to jMr. E. R. 

 Warren, curator of the museum at Colorado College, and to Mr. 

 Herman Douthitt, of the University of Illinois, for numerous speci- 

 mens of rodent nematodes. ISIany of the nematodes furnished me by 



Proceedings U. S. National Museum, Vol. 50— No. 2131. 



10600°— Proc.N.M.vol.50— 16 1 1 



