PARASITES OF FISHES OF THE WOODS HOLE REGION. 
485 
CESTODES. 
'3. Dibothrium punctatum Rudolphi. Intestine. 2, pp. 731-736, pi. n, figs. 1-4. 5, p. 430. 7, p. 284. 
July 21, 1899; 2, length 8 mm. and 180 mm. Aug 2, 1900; 1. 
4. Larval cestodes (Scole.v polymorphus Dujardin) . Free in intestine. -I, pp. 789-792, pi. lxi, tigs. 4-15. 
Aug. 2, 1900. 
5. Rhynchobothrium imparispine Linton. July 21, 1899. Encysted on viscera. See 5, p. 799, etc. 
Other Rhynchobothrium cysts not identified July 21 and August 6, 1899. 
THEM ATOIIES. 
6. Distomum vitellosum Linton. Intestine. July 21, 1899; about 45. See 7, p. 290. 
7. Distomum simplex Rudolphi. Intestine. Aug. 16, 1899; 25, length 2 mm. to 4 mm.; ova, 0.099 mm. 
and 0.055 mm. in the two principal diameters. 
8. Distomum sp. Intestine. [PI. xxxtr, fig. 359, and pi. xxxm, figs. 360-362.] Aug. 16, 1899; 5. 
Aug. 2, 1900; 1. 
These are small fusiform distomes with the following diagnostic characters: Body smooth, 
fusiform, thickest about the middle, tapering nearly equally to each end. Anterior sucker subterminal, 
circular, aperture somewhat triangular in preserved specimens. Acetabulum a little in front of 
middle, larger than oral sucker, aperture nearly circular. Pharynx subglobular, close to oral sucker, 
oesophagus distinct. Intestinal rami simple, extending to the ovarjn Vitellaria distributed in the 
median regions of the body from testes to pharynx. Testes two, rather large, placed a little diagonally 
on the median line near posterior end of body. Ovary smaller than testes, subglobular or slightly 
lobed, situated in front of anterior testis and to the right. Ova few, large, in front of ovary. Cirrus 
pouch to right of acetabulum. Genital aperture about halfway between acetabulum and oral sucker, 
to right of median line, at about midway between pharynx and acetabulum. Dimensions of living 
specimen, in millimeters: Length, 2.57; diameter, anterior 0.25, middle 0.93, posterior 0.21; diameter 
of oral sucker 0.21, of acetabulum 0.36; anterior testis, length 0.43, breadth 0.36; posterior testis, 
length 0.43, breadth 0.37; ova, 0.065 and 0.041 in the two principal diameters. Length of another 
specimen, 1.57. Dimensions measured from transverse sections: Diameter of oral sucker 0.19, of 
acetabulum 0.33, of ovary 0.17, of testes, each 0.3. The ratio of oral sucker to acetabulum is somewhat 
different from the foregoing, their diameters in one of thespecimens being 0.14 mm. and 0.17 mm. This 
for a specimen in glycerine. This species has some resemblance to D. commune Olsson. Its resemblance 
to the fusiform distome which 1 have referred to I), bothryophoron Olsson is only superficial. 
Pseudopleuronectes americanus, Flat-fish , Winter Flounder. 
FOOD. 
A specimen examined August 16, 1899, had in the alimentary canal large numbers of shrimps and 
other small crustaceans and one small fish. Four small specimens from Katama Bay, August 30, had, 
in their alimentary tracts, both univalve and bivalve shells, small crustaceans, and annelids. An equal 
number, also small, from same locality, July 27, 1900, contained nereis and fragments of red seaweed 
with sand. 
ACANTHOCEPHALA. 
1. Echinorhynchus acvs Rudolphi. Intestine. 1, pp. 492-493, pi. v, figs. 7-13. 3, pp. 525-528, pi. 
liii, figs. 1-11, and pi. lx, figs. 89, 90. 7, p. 284. 
In eleven lots in U. S. National Museum collection, seven of them collected by V. N. Edwards in 
October, November, and December, 1887, 1888, the others taken off Newport at Fish Commission 
dredging stations Nos. 789, 796, 861. In most of these lots the specimens are numerous, 350 having been 
counted in one of them. Found in this host July 21 and August 30, 1899, and July 27, 1900. 
NEMATODES. 
2 . Immature nematodes (Ascaris). 
These resemble the forms mentioned under P. oblongus , No. 2, July 27, 1900. 
2a. Ascaris sp. [PI. ix, figs. 88,89.] 
One specimen, a male, collected July 23, 1889. Moderately attenuate anteriorly and very little 
