PARASITES OF FISHES OF THE WOODS HOLE REGION. 
479 
NEMATODES. 
2. Immature nematodes. 
Rather numerous; different sizes, but all small and immature. Dimensions of one in millimeters: 
Length, 18; diameter, anterior 0.09, middle 0.6, at base of oesophagus 0.38, at anal aperture 0.19; 
distance of anal aperture from posterior end, 0.25; length of oesophagus, 0.65. Diverticulum from 
oesophagus at its juncture with the intestine. 
TREMATODES. 
3. Distomum sp. [PI. xxix, fig. 330.] 
A small number obtained from the intestine. These resemble I). tenue, but oral spines are 
wanting. The following characterization is based on alcoholic specimens: Body elongate, linear, 
depressed; neck slightly elongate, equaling about one-fifth of the whole length, armed with minute, 
flat spines; mouth unarmed; oral sucker somewhat smaller than acetabulum, nearly globular, but 
with notch on posterior inner border; acetabulum nearly globular, transverse diameter exceeding the 
length; pharynx oblong, separated by a distance equal to its length from the oral sucker and followed 
by an oesophagus of equal length; intestinal rami simple, elongate, extending to near the posterior 
end of the body; testes, two in posterior half, occupying nearly whole diameter of the body, separated 
from each other by a space equal to the diameter of each; anterior testis preceded by the globular 
ovary; ova relatively few (50, more or less) and large; vitellaria generally distributed in the body 
back of acetabulum, especially at posterior end and along margins, in transverse sections appearing as 
subglobular bodies around the periphery; seminal receptacle dorsal to acetabulum; genital opening 
in front of the acetabulum and close to it on the median line. 
Dimensions of specimen cleared in acetic acid, slightly compressed, in millimeters: Length, 3.62; 
diameter, middle of neck 0.32, maximum 0.5, near posterior end 0.3, transverse of oral sucker 0.13 
(in another specimen 0.11), transverse of acetabulum 0.17 (in another 0.13); pharynx, length 0.12, 
breadth 0.07; diameter, of ovary 0.23, of anterior testis 0.32, of posterior testis 0.35; ova, 0.07 and 0.04 
in the two principal diameters. Spines seen only on the neck, longest on ventral side of neck, where 
they are about 0.006 mm. in length. In one specimen the oral sucker nearly equaled the acetabulum, 
the diameters being 0.27 and 0.29 mm. These specimens resemble I), increscens Olsson, but differ 
from that species in the proportions of the suckers and in the position of the genital aperture. 
Brosmius brosme, Ling. 
U. S. National Museum collection. The label reads: “Ling, stomach, U. S. Fish Commission 
steamer Albatross, station 2577, 1885.” This station was established September 4, 1885, off Marthas 
Vineyard; depth, 32 fathoms. 
NEMATODES. 
1. Ascaris sp. Immature. Stomach. 
Ten and 3 fragments. Length, about 25 mm.; attenuate anteriorly, thickened toward posterior 
end, which is short-pointed and mucronate; surface of body crossed by fine transverse stride, most 
easily seen toward the posterior end. Dimensions in millimeters of a male and a female, the 
dimensions of the male given first: Length, 25 and 25; diameter of head 0.2 and 0.2, 2 mm. back of 
head 0.35 and 0.45, middle 0.50 and 0.63, 2 mm. from posterior end 0.6 and 0.62, at anal aperture 0.15 
and 0.3; distance of anal aperture from posterior end, 0.18 and 0.4; length of head, 0.15 and 0.17. The 
breadth of the upper lip in the male was 0.14 and its length 0.15; length of eopulatory spines 1.3, of 
oesophagus 3; no papillse were made out. Some variability was noted in the proportions of the upper 
lip in different specimens. There was, however, but little difference between the length and the 
breadth. The length was not less than the breadth, but it did not exceed the breadth much in any case. 
Nematonurus goodei ( Macrurus asper ) . 
NEMATODES. 
1. Ascaris linstowi Sp. nov. Stomach. [PI. iii, figs. 23-25, and pi. iv, figs. 26-28.] 
Two specimens, a male and a female, from this deep-water fish were collected from a fish taken 
by the U. S. Fish Commission off the southern coast of New England in 1884. While these specimens 
resemble Linstow’s A. macruri and still more closely his A. macruroidei (Challenger Report, vol. xxm, 
part lxxi, p. 7, 8, pi. i, figs. 10, 11, text figure 1) , they can not be referred to either. The bodies are 
