COOPERIA BISONIS, A NEW NEMATODE FROM THE 
BUFFALO 1 
By Eloise B. Cram 
Zoological Division , Bureau of Animal Industry , United States Department o 
Agriculture 
INTRODUCTION 
In material collected during post¬ 
mortem examinations of buffalo at 
the National Buffalo Park, Wain- 
wright, Canada, in January and Feb¬ 
ruary, 1923, by S. Hadwen and A. E. 
Cameron, and sent to the Bureau of 
Animal Industry, U. S. Department 
of Agriculture, there were numerous 
specimens of Cooperia which proved 
to be a new species. It is to this 
nematode that Cameron 2 refers in 
his “Notes on Buffalo” and which, 
through some lapsus, was designated 
Haemonchus ostertagi. The present 
writer, however, does not find that 
any of the specimens attain the length 
described by him—14 
mm. for the female. 
Cameron notes as the 
pathological picture an 
inflammation of the 
mucous membrane of 
the fourth stomach and 
duodenum of the buf¬ 
falo. 
SPECIFIC DIAGNOSIS 
Cooperia: Cuticle of 
head (fig. 1) markedly 
expanded, followed by 
a sharp constriction 
and then a second flar¬ 
ing out for a short dis¬ 
tance. Cuticle shows 
deep transverse stria- 
tions throughout di¬ 
lated region. The 
nerve ling surrounds 
the esophagus at a 
point about three- 
fourths of the length 
of the esophagus from 
Fig. l — Cooperia its anterior end. 
»t s S™itt ntedor M.ale .—The male is 
extremity tQ ? y mm ]ong by 
175 to 190 u in maximum width just ante¬ 
rior to the bursa. Head 37 m wide, 
o-i mm 
narrowing down to 33 m posterior to 
the cuticular dilation. Esophagus 357 
to 382 u long by 20 m in diameter through¬ 
out about three-fourths of its length, 
increasing to 33 m in maximum diameter 
near the posterior end. Free margins 
of bursa delicately striated. Lateral 
lobes of bursa (figs. 2 and 3) curved in¬ 
ward; median lobe divided in two by 
a small median incision. The externo- 
dorsal ray is the most slender of the 
paired rays, the others thicker in 
Fig. 2 .— Cooperia bisonfs. Bursa of male; lateral view 
the following order: The ventro- 
ventral, postero-lateral, medio-lateral, 
latero-ventral, and lastly the externo- 
lateral, which is by far the thickest. 
The total length of the dorsal rav is 
249 to 257 m; the stem (149 to 158 u 
long to the point of division) bifurcates 
to form a U-shaped arch. Each branch 
soon after its division from the main 
stem gives off exteriorly a thick, 
thumblike projection about 50 m long, 
the free distal half being bent ventrally. 
1 Received for publication June 30, 1924; issued June, 1925. 
2 Cameron, A. E. notes on buffalo: anatomy, physiological conditions and parasites. Vet. 
Jour. 79: 331-336. 1923. 
Journal of Agricultural Research, 
Washington, D. C. 
( 571 ) 
Vol. XXX, No. 6 
Mar. 15, 1925 
Key No. A-91 
