Pearse—Parasitic Worms From Wisconsin Fishes. 149 
Host: the short-nosed gar, Lepisosteus platostomus Rafinesque. 
Description: Body slender; length 2.4 mm.; width, .25 mm.; 
covered with sharp spines, which decrease in size posteriorly. In 
the region of the pharynx there are about fifty spines on the cir¬ 
cumference of a cross section of the body. The diameter of the 
acetabulum is slightly greater than that of the oral sucker, which 
measures .08 mm. The acetabulum is at the posterior end of the 
anterior seventh of the body. 
A slender prepharynx is present. The pharynx measures 
.012 mm. in length and .088 in diameter. The slender esophagus is 
about twice as long as the pharynx. The intestinal rami are slen¬ 
der, join the esophagus more than the length of the esophagus 
anterior to the acetabulum, and extend nearly to the posterior 
end of the body. 
The genital pore lies on the median line, just anterior to the 
acetabulum. The testes are ellipsoidal, their longest axis being in 
the same direction as that of the body. They are about equal 
in size, measuring .18 mm. in length. The anterior one is situated 
on the left side at the beginning of the posterior third of the body. 
The posterior one is slightly toward the right side, just in front 
of the posterior sixth of the body. The cirrus sac is long, thick, 
and somewhat sinuous, extending from some distance posterior to 
the acetabulum to the genital pore. 
The ovary is ellipsoidal and about half as long as a testis. It is 
situated near the middle of the body, somewhat toward the left 
side. The vitelline glands are small, irregular in form but gen¬ 
erally spherical; and distributed along each side of the body from 
a little posterior to the acetabulum to the posterior testis. The 
uterus is coiled from the genital pore to the posterior end of 
the body. It usually contains a couple of hundred eggs which are 
elliptical, without a distinct cap, and measure .04 mm. in length. 
Eleven specimens, including the type, were taken from the in¬ 
testine of a short-nosed gar on July 11, 1920. Four other speci¬ 
mens were found in bullheads caught in the slews at the outlet of 
Lake Pepin: three in an Ameiurus natalis on July 6, 1920; one in 
an Ameiurus nehulosus, July 7, 1920. 
Crepidostomum illinoiense Faust 
(Fig. 7) 
Specimens studied: Cat. No. 7626, U. S. National Museum; June 
25, 1920; Lake Pepin, Wisconsin; Collector, A. S. Pearse. 
