FISH PARASITES COLLECTED AT WOODS HOLE. 
277 
13 . Clupea harengus, Herring. 
September 5; one, young; stomach with enormous numbers of copepods of several species, young 
shrimps in large numbers, and numerous crabs in the megalops stage. The fish was taken with a dip 
net at the surface where it was feeding. A few small cysts containing blastocysts were found on the 
viscera. The blastocysts contained larval Rhynchobothria, the hooks of which agree with those 
figured in my report on larval cestodes (pi. lxiii, fig. 5). The longer hooks measured about 0.017 mm. 
One of the cysts, average, measured 2 mm. in length and 1.4 mm. in the shorter diameter. One encap- 
snled nematode was found, immature. 
14. Brevo'ortia tyrannus, Menhaden. 
(1) July 21; five; stomachs empty. 
Elongated cysts and blastocysts on viscera ( Synbothrium ) (?) (Larval Cestode Parasites of 
Fishes, pp. 815-820, pi. lxviii, figs. 7-12.) 
(2) August 15; two; stomachs empty save sand and fine material not identifiable with lens. 
Cestodes: Three elongated cysts on viscera aud a considerable number of larval cestodes of 
same general type as those found in cystic duct of squeteague, although the head seemed to be 
proportionally larger; red pigment back of head observed in some. (Larval Cestode Parasites of 
Fishes, pp. 789-792, pi. i.xi, figs. 4-15.) 
Nematodes: Three small specimens, very slender, and about 8 mm. in length. 
15 . Cyprinodou variegatus, Short Minnow. 
July 23; two, each with several tumors caused by psorosperms ( Myxoholus lintoni Gurley). 
August 23; another specimen, which had been kept for a month in an aquarium, also with 
tumors. On the surface of the tumors a number of small white specks were noticed; this was after 
the specimen had been lying overnight in 2 per cent formalin; these specks were on the surface and 
looked like masses of coagulated mucus. When transferred to a slide aud examined under considera- 
ble magnification they were found to be definitely limited clusters of psorosperms. When flattened 
under the cover glass they became elliptical in outline. 
Dimensions in millimeters: Length of elliptical mass, 0.25; breadth, 0.2; length of single psoro- 
sperm, 0.0141; breadth, 0.010; length of oval bodies, 0.004. 
No special search was made for this parasite. Dr. Gorham reported that other specimens simi- 
larly affected were seen earlier in the summer. Several specimens were taken during the summer 
with these tumors, but no formal record was kept of them. 
16 . Tylosurus marinus, Gar-fish. 
August 27; three, small; stomachs of two empty, other with small fish (silverside). Larval 
cestodes with twored pigment spots in neck in intestine. (Larv. Cost. Parasites of Fishes, pp. 789-792). 
Gasterostonmm sp. one, in intestine; see page 298 (fig. 91) for description. 
17 . Sarda sarda, Bonito. 
(1) July 20; three; stomachs empty. 
Tetrarhynchns hicolor (Larval Cestode Parasites of Fishes, pp. 813-815, pi. lxviii, figs. 1-6), 
from cysts under peritoneum. 
Gasterostonmm arcuatum sp. nov. See page 297 for description ; very numerous in pyloric crnca 
and intestine. 
One small nematode, immature, enc-apsuled on serous coat of intestine. 
(2) July 23; one; a small shell in stomach. External copepod parasites in mouth. 
One larva in blastocyst, enveloped in a delicate cyst; colorless or white with yellow blotches 
at the ends. This was found in the muscular tissue near the anus. After removal from the cyst it 
was active and crawled with progressive motion on the bottom of a watch glass. It appears to be 
T. hicolor. 
(3) July 28; two; stomachs empty. No parasites found except copepods, two on one and one 
on the other, in mouth. 
