426 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
2. Acanthocheilus nidifex Linton. Stomach. 7 , pp. 270, 271, 303, pi. xxxiii, figs. 116-119. 1899, from 
one host, 3 in pits of mucous membrane of stomach. Ova, kept in sea water, which on 
August 20 showed only early stages of cell division, on August 23 contained active embryos. 
CESTODES. 
3. Orygmatobothrium paulum Linton. Spiral valve. 5 , p. 444, pi. xxxm, figs. 7, 8. 
4. Thysanocephalum crispim Linton. Spiral valve. 1 [Phyllobothrium thysanocephalum], pp; 464-468, 
pi. n, figs. 1-12. 2, pp. 823-824. pp. 543-556, pis. lxi-lxvii. 5 , p.448. 7,p. 271. See 
also 4 , p. 792, pi. lxii, figs. 10-11, for mention of larva from the squid. Aug. 19, 1899; from 
one host, 113, large and small. 
5. Monorygma sp. Spiral valve. 7 , p. 271. See No. 3 under Isurus delay i. 
6. Tetrarhynchus bicolor Bartels. Stomach. 4 , p. 813-815, pi. lxviii, figs. 1-6. 7 , p. 271. Aug. 19. 
1899, several attached to and penetrating the stomach wall. 
Carcharinus milberti, Blue Shark. 
(Incorrectly referred to Prionace glauca in paper cited below. ) 
FOOD. 
Two small specimens, 41 feet long, taken August 5, 1889. Stomachs contained half-digested fish 
(bonito). A specimen taken off Gay Head by the schooner Grampus , July 30, 1900, and examined by 
Mr. C. W. Stone, was reported to have had fish of different kinds in the stomach, one of which was a 
flounder. This specimen measured feet. 
NEMATODES. 
1. Immature nematodes. Spiral valve. Embryonic cuticle still partly adhering. Specimens probably 
introduced with food, July 30, 1900. 
CESTODES. 
2. Anthobothrium laciniatum Linton. Spiral valve. 2, pp. 754-759, pi. in, figs. 10-13; pi. iv, figs. 1-3. 
5 , p. 439. July 30, 1900, 4, very small. 
3. Crossobothrium angustum Linton. [ Orygmatobothrium anguslum Linton.] Spiral valve. l,pp. 468- 
469, pi. ri r, figs. 1-3. 2, pp. 796-799, pi. vii, fig. 3. 5, p. 443. 
4. Monorygma sp. Spiral valve. July 30, 1900, 27, small. See remarks on No. 3, under Isurus dekayi. 
5. Phoreiobothrium lasium Linton. 1, pp. 474-476, pi. iv, figs. 24-29. 2, pp. 819-820. 5, p. 447. 
7 , pp. 272-273. 
6. Platybothrium parvum sp. nov. Spiral valve, July 30, 1900, 253. 
Probably the same species mentioned in 7 , p. 300, pi. xxxn, figs. 98, 99. The hooks are 
identical and should have been selected as a generic character. The bothriaare provided with two costte 
on the posterior end and an auxiliary sucker in front of hooks. Neck elongated and densely spinose. 
The bothria in these specimens differ from any of the genus seen before in that they are trough-shape, 
the head thus bearing a strong superficial resemblance to Phoreiobothrium. The ripe segments are 
elliptical and loosely attached, making a moniliform chain. Longest specimens, 10 to 15 mm. 
Dimensions of one of the larger specimens in millimeters: Length, 15; length of head, 0.54; breadth 
of head in front, 0.41; diameter of neck immediately behind the head, 0.11; length of last segment, 
0.67; breadth, 0.47. The first distinct segments began about 5 mm. back of head. 
7. Bhynchobothrium tenuispine Linton. Spiral valve. 2, pp. 837-838, pi. xii, figs. 1, 2. 5, pp. 448-449, 
pi. xxxiv, fig. 8. 
Carcharinus obscurus ( Carcharias obscurus), Dusky Shark. 
FOOD. 
Fish, among which menhaden and squeteague have been recognized. The stomach of a specimen 
examined August 1, 1899, contained a large quantity of oil in globular masses about the size of average 
peas. All the specimens examined in 1899 and 1900 were small— 4J to 5 feet. 
ACANTHOCEPHALA. 
1. Echinorhynchus agilis Rudolphi. Spiral valve. 1, pp. 490-492, pi. v, figs. 1-6. 
