PARASITES OF FISHES OF THE WOODS HOLE REGION. 
451 
CESTODES. 
6. Dibothrium prctssiceps Rudolphi. 
July 21, 1900; 36 scolices obtained from one fish. The longest of the strobiles, none of which 
are mature, was 40 mm. Scolex nearly globular; when at rest broader than long in some. (See No. 3, 
under Merluccius bilinearis.) [PI. xvn, figs. 142-144.] 
7. Rhynchobothrium bulbifer Linton. Cysts on viscera. 4 , p. 793. Aug. 3, 1900. 
8. Rhynchobothrium speciosum Linton. Cysts on viscera. 4 , pp. 801-805, pi. lxiv, figs. 13-14, and 
pi. lx v, figs. 1-7. 7, p. 278. July 21, 23, 1900; Aug. 13, 1900. 
9. Tetrarhynchus bisulcatus Linton. 
Usually present in great abundance in cysts in the stomach wall; best seen by separating the 
muscular coats from the submucosa, when the cysts will be seen lying in the submucosa. 1, p. 486 
(R. bisulcatus). See also 4 , pp. 810-811. 7, p. 278. July 21, 23, 1900; Aug. 1, 1900. 
10. Tetrarhynchus erinaceus Beneden. Cysts on viscera. See 4 , pp. 811-812, pi. nxvir, figs. 1-8. Aug. 
13, 1900. 
11. Otobothrium clipsacum Linton. 4 , pp. 806-807, pi. lxvi, figs. 1-5. 
12. Synbothriuni filicolle Linton. Cysts on viscera. 4 , p. 818. 7, p. 278. July 21, 23, 1900; Aug. 
I, 13, 1900. 
In specimen examined Aug. 1 several large cysts were found on spleen, pyloric caeca, and intestine, 
and one in submucosa of stomach. Cysts with degenerate contents. July 23, Aug. 11, 1900. 
13. Larval cesmUes {Scolex polymorphus Dujardin ) . Small, free in intestines. See 4 , pp. 789-792. Aug. 
26, 1899; July 21, 1900. 
TKEMATODES. 
14. Distomum monticellii Linton, intestine. See t», pp. 518-520, pi. xliv, figs. 2-8. July 27, Aug. 
II, 14, 1899; 10 in all. 
15. Distomum sp. [PI. xxxi, figs. 341-344.] 
Brief mention is here made of a few small distomes found on the following dates: August 14, 17, 
26, 1899; August 18, 1900. They are characterized by being covered with low, fiat spines as in D. 
dentaturn, mouth unarmed, suckers of about equal size, and (esophagus longer than pharynx. The 
body is white, depressed, usually oval, but elongated forms also seen, both forms occurring in same 
lot. Similar forms were found in the flounder (fig. 345) and scup \ fig. 346) ; spineless distomes agreeing 
in other respects with these were seen in the flounder (fig. 352), and in the butter-fish (fig. 353) ; a 
related form from the mummichog is shown in fig. 354. 
16. Distomum vitellosum Linton. [PI. xxx, figs. 337-339.] See 7 , p. 290, pi. xxxvii, figs. 38, 39. Aug. 
26, 1899; July 21, 1900; Aug. 18, 25, 29, 1900. 
I here record examples from the blue-fish of a species of distome found in a number of hosts which 
I have entered in my notes as small, cylindrical, with prominent acetabulum. In many cases, where 
tap water was used for washing out the contents of the alimentary canal, distomes were found which 
had been killed by contact with the fresh water. Under such conditions the distome assumed a 
characteristic position in which the neck was reflected nearly at right angles to the body. In sea water 
or in salt solution the worm remains active and is then seen to be of very varying form. The species 
is near D. simplex. See remarks under No. 6 of Microgadus. 
17. Microcotyle sp. From gill filaments. [PI. xxvii, figs. 299-306.] 
Prof. C. B. Wilson, while collecting parasitic copepods from the gills of a large blue-fish, September 
3, 1900, called my attention to some trematode worms. These belong to the genus Microcotyle. 
They are slender, thin, and strap-like worms, attenuate both anteriorly and posteriorly. They attach 
themselves to the gills by the posterior part of the body, which, for a third of its length, is provided 
with a great number of minute suckers. The worms were very active with the body proper, although 
remaining firmly attached to the gill filaments, in which position they were killed. They were 
transparent, bluish white, the vitellaria marginal and dark brown. They were collected just as I was 
about to leave Woods Plole, so that but little time was available for the study of the living worms. 
