454 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
from which, upon further pressure, a larval cestode (Rhynchobothrium sp. ) could be obtained. Forty 
of these cysts were counted in a space 4 nun. square. 
Similar conditions were observed in a butter-fish brought to me by Mr. E. E. Tyzzer, August 17, 
1900, and in another examined the following day. 
In these cases enormous numbers of cysts were seen in the muscles. They were most abundant 
on the ventral side of the vertebral column, between the subvertebral spines. They were also scattered 
through the dorsal region, lying deep among and near the dorsal vertebral spines. The cysts are 
small, oval, about 1 mm. in length and somewhat less in shorter diameter. One measured 1.3 mm. in 
length and 0.87 mm. in diameter. The contained blastocyst measured 0.87 and 0.67 mm. in the two 
principal diameters. Dimensions of the larva in millimeters: Length, 0.7; bothria nearly circular, 0.3 
in diameter; diameter of neck, 0.1. Contractile bulbs very short. 
6. Tetrarhynchus. Cysts on peritoneum. 4 , p. 809. Some of these may belong to the genus 
Rhynchobothrium. 
7. Tetrarhynchus erinaceus Beneden. See 4 , pp. 811-812, pi. lxvii, figs. 1-8. July 27, 1900; several 
on viscera. 
8. Larval cestodes (Scolex poly morphus Dujardin). Free in intestine. See 4, pp. 789-792. Found in 
summers of 1899 and 1900. 
9. Dibothrium angustatum Rudolphi. Sept. 1, 1900. A few small specimens, the longest less than 
10 mm. in length; head about 1 mm. long and 0.3 mm. or less in width. Very active. Joints 
narrow and irregular. Immature. 
TREMATODES. 
10. Distonmm gulosum sp. nov. [PI. xxvm, fig. 315-317.] 
Appendiculate distomes, apparently new. July 26, 1899; 16 specimens obtained from a lot of 
4 butter-fish. Butter-fish were examined on seventeen different occasions in 1899 from July 17 to 
August 26. Dimensions of living specimens, slightly compressed, in millimeters: Length, 10; maximum 
diameter, median, 1.14; length of appendix, 3.6; ’diameter of anterior sucker 0.36, of acetabulum 0.38; 
distance between suckers, 0.1; diameter of testes 0.47, of ovary 0.28; ova, 0.017 and 0.010 in the two 
principal diameters. 
Body slender; neck tubular, slightly arcuate; neck and anterior part of body crossed by fine 
lines, which produce a sharply serrate outline; oral sucker nearly globular; mouth slightly subterminal, 
with longitudinal opening; pharynx tubular, almost as long as the oral sucker; oesophagus none; 
intestinal rami extending into the appendix, which is long and slender; genital aperture on ventral 
border of mouth; acetabulum nearly globular, its diameter not differing much from that of the oral 
sucker; seminal vesicle some distance behind acetabulum, followed posteriorly by the two smallish 
subglobular testes, which lie end to end; ovary globular, a short distance behind the testes; vitellaria 
about the middle of the body, behind the testes, tubular, as many as six tubules showing in sections; 
uterus voluminous, its folds extending into the appendix; ova numerous, small. Dimensions of a 
specimen mounted in glycerine, in millimeters: Length, 7.5; oral sucker, length 0.36, breadth 0.36; 
pharynx, length 0.33, breadth 0.18; acetabulum, length 0.32, breadth 0.33; distance from anterior end 
to acetabulum, 0.87; distance between acetabulum and testes, 1; distance between testes and ovary, 
0.19; diameter, of neck 0.36, middle of body 0.65, posterior 0.15, of anterior testis 0.28, of posterior 
testis 0.25, of ovary 0.23; ova, 0.017 and 0.010 in the two principal diameters. 
The alcoholic specimens show at least one important variation from the living worm, viz, in the 
relative size of the suckers. In one the suckers were of equal size, in another the acetabulum was 
less, and in another. the anterior sucker was larger but of less transverse diameter than the acetabulum. 
The vitellaria are tubular, showing as many as six distinct masses in transverse sections of the body. 
11. Distornum. sp. [PI. xxxii, fig. 353.] 
Mention is here made of a few small distomes which require further study before a specific name 
can be assigned to them. Specimens were found on July 24 and August 14 and 23, 1899, which were 
small, oval, translucent, bluish-white, and spinose. Dimensions of a living specimen in millimeters: 
Length, 0.78; diameter of oral sucker, 0.064; of ventral sucker, 0.057. 
These specimens suggest D. pyriforme. Others collected July 26 and August 2, 15, 20, and 23, 1899, 
resemble these, but the habit of the body is much more slender. [Fig. 353.] Some of these suggested 
Distornum sp. from the scup [ 7 , p. 296, pi. xxxix, fig. 72], and Distornum sp. from the puffer [ 6 , pp. 
537-538, pi. ltii, figs. 1, 2] . Spines can not always be made outon these forms. 
