428 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
male apparently equal. Anal aperture transverse with a chitinous toothed plate on its posterior border. 
Preanal papillae, as seen on left side, about 24, arranged somewhat in groups of three; on right side they 
appear to be fewer and larger; postanal papillae, 10 seen on left side and 7 on right, with 6 nearly 
median near the tip. Dimensions in millimeters: Male, length, 16.5; diameter of head 0.11, 1 mm. 
from anterior end 0.36, maximum 0.56, 1 mm. from posterior end 0.47, at anal aperture 0.27; distance 
of anal aperture from posterior end, 0.27; length of oesophagus, 1.8. Female, length, 30; diameter 
of head 0.13, 1 mm. from anterior end 0.42, maximum 0.86, 1 mm. from posterior end 0.71, at anal 
aperture 0.28; distance of anal aperture from posterior end, 0.28; length of oesophagus, 2. 
2. Ichthyonerna sp. 
From liver, collected by Dr. Howard Ayers, August 17, 1889. The specimen is the posterior end 
of a female, 108 mm. in length and 0.7 mm. in diameter and tapering at posterior end. 
3. Immature nematodes. [PI. xiv, figs. 183-184.] 
Fragment from intestine, July 28, 1886, evidently introduced with food; length, 15 mm.; diameter, 
0.45 mm.; still inclosed in hyaline embryonic cuticle; posterior end bluntly rounded; diameter nearly 
uniform, irregularly interrupted by indentations. July 31, 1899; small fragment from intestine. 
C'ESTODES. 
4. Anthobothrium ladniatum Linton. Spiral valve. July 31, 1899; from one host, 4. Not recorded 
before from this host. See under Carcharinus obscurus, No. 3. 
5. Phoreiobothrium lasium Linton. Spiral valve. 7 , p. 273. See under Carcharinus obscurus, No. 6. 
July 31, 1899; from one host, 4. 
6. Platybothrium parvurn sp. nov. Spiral valve. 7 , pp. 273 and 300, pi. xlii, ligs. 98, 99. July 31, 
1899; from one host, 2. See under Carcharinus milberti, No. 6. 
7. Otobothrium crenacolle Linton. Spiral valve. 2 , pp. 850-853, pi. xm, figs. 9-15, and pi. xiv, figs. 
1-4. 7 , p. 273. 
8. Tetrarhynchus. Encysted in intestinal wall. 4 , p. 808. 
9. Txnia sp. [PI. xxv, ligs. 274-281; pi. xxvi, fig. 282.] 
July 31, 1899; several attached to mucous membrane of intestine. About a dozen were attached 
firmly, their heads embedded in the intestinal wall within a space about 10 mm. square. Specimens not 
measured when first taken. The alcoholic specimens are not in good condition, being rather fragile. 
Dimensions of two specimens, in millimeters: Length, 14 and 24; diameter of head, 0.86 and 0.70; 
diameter of neck, 0.60 and 0.50; length of last segment, 0.50 and 0.70; breadth of last segment, 2 and 
2.40; diameter of suckers, 0.34 and 0.22. Length of a free segment, 8.5; breadth, 2.5. Some of the ova 
nearly circular in outline, with the diameter 0.17; others ovate with maximum diameter as much as 
0. 22. one 0.17 and 0.21 in the two principal diameters. Cirrus long, armed with hooks; length of 
hooks, 0.014. This species suggests Txnia gibbosa Leidy, from a species of Lanina inhabiting the 
Pacific coast of North America. 
Alopias vulpes, Thrasher. 
The viscera of one specimen were examined July 6, 1887, but no entozoa were found. Another, 
examined August 20, 1900, had remains of small fish in the intestine. No entozoa found. 
Carcharias littoralis ( Odontaspis littoralis ) , Sand Shark. 
FOOD. 
Fish (menhaden, sea bass, scup, and butter-fish noted) and squid. 
ACANTHOCEPHALA. 
1. Echinorhynchus carcliarix. 3 , pp. 536-537, pis. lix, lx, figs. 81-84. 
2. Echinorhynchus acus Rudolphi. Aug. 12, 1899, from one host 1. Spiral valve. Probably introduced 
with food. 7 , p. 273. 
NEMATODES. 
3. Acanthocheilus sp. Stomach. July 21, 1899, from one host 3; Aug. 9, 1899, from one host 1; Aug. 
12, 1899, from one host 1 . 
These worms are rather plump, thickest in the middle and tapering equally to each end. Length, 
34 to 44 mm.; diameter reaching 2 mm. Mouth provided with three minute lips. No males seen. 
