PARASITES OF FISHES OF THE WOODS HOLE REGION. 
481 
TEEMATODES. 
5. Distomumlseve Linton. 6, pp. 517-518, pi. xliii, figs. 5-8; pi. xliv, fig. 1. 
Hippoglossus platessoides, Sand-dab. 
NEMATODES. 
1. Ascaris incurva Rudolphi (?) ; young. 
Two immature specimens obtained from rectum of a sand-dab by Mr. B. A. Bean. The fish was 
taken off Race Point in 34 fathoms, August 25, 1899. The head agrees with this species; the tail, 
however, is too blunt unless they are immature males, which appears to be the case. Dimensions in 
millimeters: Length, 25; diameter, head 0.20, at base of oesophagus 0.58, middle 0.84, at anal aperture 
0.23, one millimeter from posterior end 0.51; length of head 0.19, of oesophagus 3.84; distance from 
anal aperture to posterior end, 0.22. There appears to be an anterior prolongation of intestine parallel 
with oesophagus, 1.45 mm. in length. The intestine near the posterior end is capacious, with crumpled 
walls. 
2. Iclithyonema sp. Intestine. 
A slender nematode collected August 8, 1899. Almost the entire body was filled with elliptical 
ova 0.041 and 0.024 mm. in the two principal diameters. Slender attenuate anteriorly, more rapidly 
attenuate and acute at posterior end. Other dimensions in millimeters: (Esophagus at anterior end 
0.058 in diameter, nearly cylindrical for a distance of 0.43, where it increases abruptly from 0.072 to 
0.094, increasing thence to the base, where it is 0.26 in diameter; whole length of oesophagus, 3.9; 
length of worm, 15; diameter, anterior 0.06, middle 0.4. 
Paralichthys dentatus, Flounder. 
FOOD. 
The stomachs usually contain fish and squid. In one case 18 squid were taken from the stomach 
of a single flounder. A hermit crab along with fish, squid, small fish and crustaceans, are other 
records of contents of alimentary canals of the flounder. 
ACANTHOCEPHALA. 
1. Ecliinorhynclius acus Rudolphi. Intestine. 3 , pji. 525-528, pi. lx, figs. 89, 90. 
2. Echinorhynchus proteus Westrumb. On mesentery. 7, p. 283. 
3. Echinorhynchus incrassalus Molin. Peritoneum. 3 , pp. 533-534, pi. lviii, figs. 54-69a. July 18, 
1899. 
4. Echmorhynchus sagittifer Linton. On viscera. S , pp. 493-496, pi. vi, figs. 1, 2. 3 , pp. 535-536, 
pi. lix, fig. 80. 
NEMATODES. 
5. Immature nematodes {Ascaris). [PI. xn, figs. 143-146; pi. xm, tigs. 147-151.] 
Of very frequent occurrence, encapsuled in the mesentery and on the viscera, 1884 to 1889. 
Flounders were examined in 1899 on sixteen dates and nematodes recorded on nine of these. They 
were examined on five dates in 1900 and nematodes recorded on each date. They occurred in varying 
numbers, though only once numerous. 
6. /I scarfs (?) sp. Intestine. [PI. vn, figs. 57-61.] 
Two specimens obtained on August 9 and one on August 23, 1900; all females, active and mature. 
These worms are small, white, translucent. The mouth is relatively large and surrounded by three 
low, inconspicuous, rounded lobes, each of which is provided on its inner surface with a large number 
of minute teeth and apparently a single papilla. The body is short, cylindrical, truncate in front, 
slender pointed at posterior end. The diameter equals about one-tenth of the entire length. It is 
nearly uniform from the anterior end to the middle, or a little behind the middle; that is, about to 
the genital opening, whence it tapers very gradually toward the posterior end, narrowing rapidly just 
in front of the anus and likewise just at the anus. The tip is slender, but short acuminate. The 
intestine is capacious. A short anterior diverticulum embraces the base of the oesophagus on one side 
and a longer one on the other. The ovaries are voluminous, the genital opening a little behind the 
middle of the length. 
F. C. B. 1899—31 
