316 
IOWA ACADEMY OP SCIENCE Vol. XXIV, 1917 
body of the parasite was free from attachments, hanging limply 
in the Inmen of the lung or air sac. The heads of the males 
were not embedded in the tissues of the host, but only superfi- 
cially attached to the walls of the lung and air sac by the hooks. 
The females vary in length from eighty-two mm. to ninety- 
six mm., and are somewhat larger than the specimen described 
by Hett, while the males were from fourteen mm. to thirty mm. 
in length. The color of the females is lemon-yellow and the 
body wall is transparent and thus permits easy observation of 
the mass of embryos and digestive tract within. The males are 
pale cream in color and the body walls are opaque. 
The head is globose dorsally; ventrally it is slightly concave 
with four sharply curved hooks at the anterior edge of the con- 
cavity, two on either side of the pear-shaped month. The neck 
is markedly constricted ; the body is subcylindrical, slightly taper- 
ing to the posterior end which is blunt. There are about fifty 
annulations, though the number varies in different individuals 
from forty-eight to fifty-two. The digestive tract, which was 
gorged with blood, was readily seen in the living specimen. 
The Distome. 
The second parasite found belongs to the genus Renifer and is 
evidently a new species. It is most nearly allied to R. ellipticus 
Pratt, but differs from it in many points, as a comparison of the 
following data with those of H. S. Pratt in “Description of Pour 
Distome, Mark Anniversary Volume, 1903, will show. 
r 
“Length 6.5 mm. Maximum breadth 1.72 mm. 
Ventral surface flattened, dorsal quite convex. 
Spines seem to me lacking, except perhaps anteriorly. 
Oral sucker sub-terminal, diameter 0.52 mm. 
Acetabulum 0.74 mm. in diameter, about 1.11 mm. from oral. 
Genital pore 0.37 mm. from left edge of body. Much farther for- 
ward than in R. ellipticus, opposite the hinder edge of the oral sucker 
or anterior one-half of the pharynx. Ventral. 
Pharynx 0.296 mm. long. 
Oesophagus 0.11 mm. long. 
Intestinal coeca simple; pass beyond the testes (apparently right 
beyond the right testes). 
Union of the vasa efferentia behind the equator of the acetabulum. 
Cirrus sac about 1.24 mm. long by 0.40 mm. wide at middle.” 
These data were taken by Mr. A. R. Cooper. 
The six specimens of this species were found attached to the 
lateral walls of the coelomic cavity and on the outer surface of 
