558 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 
7.00; greatest diameter, 0.25; diameter of head, 0.20; diameter of neck, 
0.15; length of neck, 1.00; length of caudal spine, 0.15. Female, length 
15.00; greatest diameter, 0.40; diameter of head, 0.25; diameter of neck, 
0.17; length of neck, 1.20. Genital pore, 5 mm. from posterior end. 
These parasites were met with frequently in the trout of Heart Lake 
and in those of Yellowstone Lake and the river. Their favorite resting- 
place is in the alimentary canai in the vicinity of the pyloric ceca. 
ENCYSTED SPECIMENS OF D. GLOBOSA. 
This worm was also found in cysts which usually appeared as pedic- 
wated tumors within the body cavity of the trout. It frequently hap- 
pened that among the cysts of Dibothriwn cordiceps, found in the body 
cavity of the trout, there would be a few cysts which differed some- 
what in appearance from the former. These, when opened, collapsed 
on account of the liberation of a thin, watery, granular fluid, in which 
there was invariably a small nematod worm. These proved, upon subse- 
quent examination, to be specifically identical with the worms from the 
alimentary canal which I have referred to D. globosa. 
These cysts are easily distinguished from the dibothrium eysts by 
their difference in color and resistance to pressure, The cysts of Di- 
bothrium cordiceps are white, firm, and resistant. The nematod cysts 
are yellowish or flesh-colored, and are soft and yielding. Moreover, 
they are usually suspended by a peduncle and are covered by a layer 
of the peritoneum, which is richly supplied with blood vessels. The 
worm which is liberated from the cyst is altogether disproportionate in 
size to the containing cyst. The worm, even from a cyst 10 mm. in 
diameter, may be so small as to be easily overlooked amidst the granu- 
lar fluid which escapes when the wall of the cyst is ruptured. These 
cysts usually occur on the rectum or along the course of the lower 
intestine. They are sometimes found, however, in the vicinity of the 
pyloric coca. 
A cyst measuring 15 by 9 by 7 mm. in its three dimensions, which 
had been preserved in alcohol, was opened. The walls were 0.5 mm. 
thick, and the contents were granular and whitish. The cyst was cov-~ 
ered by a layer of peritoneum, which contained capillary blood vessels. 
The worm which was liberated was 8 mm. in length. Another cyst, 4 
by 5 by 3 mm. in its three dimensions, contained a small male worm 4 
mm. long. The nematods obtained from these cysts were all immature 
and belonged to the same species, Daecnitis globosa. Sections of these 
cysts show that their walls are made up of a number of concentric 
layers, rather loosely connected and often poorly defined, and with 
numerous nuclear granules in and among the layers. 
In addition to Daecnitis globosa, and associated with it, 1 found a few 
forms that I have not been able to identify. One of these, a single 
specimen of which was found, is an immature form of a rather stout 
nematod, length 14 inm., breadth 0.5 mm. It tapers gradually toward 
