PARASITES OF FISHES OF THE WOODS HOLE REGION. 
469 
A small globular cyst, yellowish, in one lot, from the viscera and several others from cysts in the 
liver in another lot contained minute distomes, which are probably young of this species. There was 
a double row of spines around the mouth, about 25 in each row. 
7. Distomes (undetermined species). [PL xxix, figs. 324— 329.] Intestine. 
On August 15, 1899, a small lot of distomes were obtained in which there are at least two distinct 
species. On account of the small number and the unsatisfactory condition of the preserved material 
I shall not assign specific names to them. They were associated with specimens of I). tenue and I), 
tornatum. 
A. (Figs. 324, 326.) One larger and one smaller specimen. The living worms were yellowish. 
Body oblong, appressed, transversely rugose, with minute scattering scale-like spines (easily over- 
looked). Oral sucker and acetabulum about equal. Aperture of mouth in smaller specimen with 
notch at anterior border (not noted in larger specimen); aperture of acetabulum a little wider than 
long. Pharynx longer than broad, apparently protruding into the oral sucker. (Esophagus, if any, 
short; intestinal rami simple, extending nearly to the posterior end. Testes two on median line 
about middle of body, the anterior testis subglobular, the posterior somewhat three-lobed. Seminal 
vesicle (made out onljr in smaller specimen) dorsal to acetabulum; genital aperture on median line 
immediately in front of acetabulum; ovary near posterior border of acetabulum, a little to left of 
median line; a seminal receptacle was made out in the smaller specimen anterior to the ovary, and 
to the left; vitellaria voluminous in posterior and lateral regions of body and extending at least as far 
forward as the acetabulum, in the smaller specimen as far as the pharynx. Ovum, in larger specimen 
only, 0.10 and 0.07 in the two principal diameters. 
The following table shows the dimensions in millimeters, the larger specimen in turpentine, the 
smaller in balsam: 
Larger 
speci- 
men. 
Smaller 
specimen. 
Length .* 
w 1 ! 
mm. 
1.10 
.37 
.17 
.18 
.17 
.21 
.08 
.11 
Length of anterior sucker 
Breadth of anterior sucker 
Length of acetabulum 
Breadth of acetabulum 
Breadth of pharynx 
B. Two specimens stained and mounted in balsam. These agree in the relative proportions of 
suckers and pharynx, in the position of the genital aperture, and the general arrangement of testes and 
ovary. The greatest difference is in the character of the vitellaria; other differences may be accounted 
for by different conditions of contraction. 
Characters common to both are: Acetabulum much larger than oral sucker, broader than long; 
oral sucker longer than broad; pharynx nearly as large as oral sucker; oesophagus short; intestinal 
rami simple, reaching nearly to posterior end; testes two on median line in about the posterior third 
of body, the anterior testis immediately preceded by the ovary, which lies a little to the right of the 
median line; genital aperture a short distance in front of acetabulum, to the left of the median line; 
the radiating muscles of the cirrus bulb are distinctly seen in ventral view upon focusing with a high 
power. 
a. ( Fig. 327. ) This specimen was probal >ly killed while flattened out under pressure. The body is 
smooth, the intestinal rami thin-walled and inflated. There is a vitelline reservoir immediately in 
front of the ovary, into which two anterior and two posterior vitelline ducts empty. The vitellaria 
are rather irregular small granular masses at the posterior end of the body and along the lateral margins 
nearly to the acetabulum. The two testes and ovary are each subglobular. 
b. (Figs. 328, 329. ) This specimen is much contracted. The body is transversely rugose, and the 
posterior region, when strongly magnified, is seen to be beset with minute, bristle-like spines. The' 
intestinal rami are slender, but. thick-walled. The vitellaria are at the posterior end of the body and 
along the margins as far forward as the pharynx; the granular masses larger and more crowded than 
in a. Testes and ovary broader than long. 
