they were secured are as follows: Center 
County, 1; Union County, 11; Potter Coun- 
ty, 3; Cameron County, 3; and Sullivan 
County, 4. 
Nematodes were found in all of the beaver 
recorded and the number found varied from 
one to several hundred. The largest num- 
ber of parasites in any of the specimens 
examined were from Union County. One 
beaver from Union County and one from 
Potter County were infected with amphis- 
tomes. A section of hemorrhagic intestine 
from one of the specimens taken from Potter 
County was preserved in formalin solution. 
Upon examination of this material I found 
a number of coccidial oocysts but these 
organisms were shrunken by the formalde- 
hyde and it was impossible to determine 
whether they were Eimeria or Isospera. It 
was impossible to sporulate any of the 
organisms preserved in this solution. Sec- 
tions of specimens of beaver from all of the 
counties with the exception of Potter County 
were taken and preserved in glycerin. This 
material was sent to Dr. R. G. Green for 
injection into guinea pigs. The injection 
of this material gave negative results in 
every case. No pathology was found in any 
 
There were two types of nematodes found, 
one, Castorstrongylus castoris, which is found 
in the colon, the other, Travassosius ameri- 
canus, which is found in the stomach. These 
two parasites were described by Edward A. 
Chapin in an article entitled "New Nema- 
todes From   North   American  Mammals," 
Journal of Agricultural Research, Vol. XXX. 
The amphistome Stichorchis subtriquetrus 
was described by Rudolphi in 1814. This 
parasite was first found in the colon of 
European beaver.