466 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
4. Tetrarhynchus elongatus Wagener. Liver. 4 , pp. 812-813, pi. lxvii, figs. 9-12. 7, p. 2S2. July 
19, 1899; 5 scolices. July 10, 1900; 6 scolices. July 30, 1899; several. July 29, 1900; several. 
One of these larvae in its blastocyst was dissected out of the liver by Mr. W. W. Francis, July 19, 
1899. Its dimensions, in millimeters, follow: Length of anterior actively motile part of blastocyst 18, 
diameter 4; length of posterior part of blastocyst 400, diameter 2. These dimensions were changed 
somewhat after the specimen had been lying in water for three or four hours. After killing, the length 
of the anterior portion was 24 mm. and of the posterior 440 mm., the diameter remaining the same as 
in the living specimen. The posterior two-thirds was embedded in the liver; the anterior third was 
on the surface, but under the serous coat. In another specimen the anterior part was 40 mm. in 
length. The posterior portion was not all dissected out. If the proportions are the same as in the 
first, it should be 800 mm. in length. The five specimens represent an aggregate length of probably 
3 meters, 2 of which are in the substance of the liver. The explanation of the great length which 
these cestodes attain in the liver of the sun-fish is doubtless to be found in the fact that the life of the 
host is very long, and therefore the time which the worm is doomed to remain in the liver after it has 
once gained a lodgment there must likewise be very long. Of course its surroundings must be congenial 
and conducive to longevity, else its tissues would, sooner or later, degenerate. Although this cestode 
appears to be invariably present in the liver of the sun-fish, it may be questioned whether the sun-fish 
is, in a strict sense, the proper intermediate host of this worm. It would indeed be a large animal, 
and one with phenomenal digestive powers, which would habitually use the sun-fish for food. 
5. Rhynchobotlirium sp. From cysts on intestine under the serous coat. July 7, 1900. [PI. xxii, figs. 
‘ 245-250.] 
Length of cyst, 27 mm. ; breadth, 16 mm. A globular portion of the cyst was of dense connective 
tissue 5 mm. thick; the space within, about 2 mm. in diameter, was filled with yellowish coagulated 
fluid. The blastocyst, which had evidently at one time occupied this space but now lay in a thinner 
walled part of the cyst, was 42 mm. in length and 5 mm. in greatest diameter. It contained a larval 
Rhynchobothrium which, when everted, measured 20 mm. in length. 
TREMATODES. 
6. Tristomum molse Blanchard. \Tristomum rudolpliianum Diesing.] Skin, gills. <5,p. 510." 7,p. 281. 
A sun-fish captured July 30, 1899, was reported by Dr. Dahlgren to have- had 138 trematodes 
on the skin. July 19, 1899; 1. This was translucent, bluish-white, with a shade of pink, especially 
toward the posterior end. Lateral areas, dark-brown. July 10, 1900; 2. 
7. Distomum macrocotyle Diesing. Intestine. 6, pp. 522-523, pi. xlv, figs. 9, 10, and pi. xlvi, figs. 1-5. 
7, p. 282. July 29, 1900; 12. 
8. Distomum contorturn Rudolphi. Intestine. 6, pp. 528-530, pi. xlviii, figs. 3-7. July 19, 1890; 3. 
9. Distomum nigrqflavuin Rudolphi. Intestine. 6, pp. 530-531, pi. xlviii, figs. 8-11, and pi. xlix, 
figs. 1, 2. 7, p. 282. July 30, 1899; 9. July 10, 1900; 2. July 29, 1900; 3. 
10. Distomum foliatum Linton. Intestine. 6, pp. 532-534, pi. xlix, figs. 3-5; pi. l, figs. 1-3; pi. li, 
figs. i-4. 7, p. 282. July 19, 1899; 1. July 10, 1900; 4. July 29, 1900; 1. 
11. Distomum fragile Linton. Intestine. <», pp. 282-295, pi. xxxiv, figs. 68-70. July 10, 1900; 
numerous. Length of living specimens, 4.2 mm. 
Many copepod parasites were seen on the sun-fish; numerous flat, scale-like forms on the skin; 
large paired forms on the gills and long lerneans with heads buried in the flesh, the body with eggs 
hanging like a dark-brown tassel from the skin. One parasitic copepod was found under the skin, 
which at that point was over an inch thick. 
Myxocephalus aeneus (Cottus xneus, Acanlhocottus emeus), Little Sculpin, Grubby. 
FOOD. 
Annelids, copepods, shrimps, and young fish found in the alimentary canals of young specimens. 
Many young flounders and shrimps taken from alimentary tracts of young sculpin from Katama Bay, 
August 28, 1900. 
ACANTHOCEPHALA. 
1. Echinorhynchus acus Rudolphi. 3, p. 525. 
