PARASITES OF FISHES OF THE WOODS HOLE REGION. 
429 
4. Ascaris sp. [Pl. xi, figs. 127-130.] 
A few specimens found in the intestine on different occasions, immature, most of them certainly 
young ascarids. They have evidently been introduced with the food and probably would not develop 
further in this host. The specimen shown in figs. 127-128 was collected August 2, 1886. Length, 17 mm. ; 
maximum diameter from middle to posterior third of body, 0.57 mm.; body crossed with transverse 
striee ; wall of intestine tessellated. Figs. 129-130 show an immature female, length, 50 mm.; diameter, 
middle to posterior fifth, 1.6 mm. 
CESTODES. 
5. Crossobothrium laciniatum Linton. Spiral valve. 1 , pp. 469-474, pl. hi, figs. 4-18. 2 , pp. 799-802, 
pl. vii, fig. 4. 5, pp. 445-446. 7, p.273. 
July 17, 1899; 20. July 21, 1899; several. Aug. 9, 1899; numerous. Aug. 12,1899; 2. Aug. 15, 
1899; 1. In this specimen the stomach was empty, the intestine contained a viscid mucus and there 
was a diseased patch of mucous membrane at pyloric end of stomach, the surface being caked and 
hard. Aug. 17, 1899; 4. Aug. 18, 1899; 55, large and small. Aug. 19, 1899; 12. July 20, 1900; 
47 from one and 16 from another, young and adult. Two small worms in this lot present some 
points of difference from the young of this species with which they were associated. Bothria provided 
with an auxiliary acetabulum as in Crossobothrium but smaller, more slender, and less mobile; body 
slender, with apparently true proglottides, which were elongated and without any indication of 
lacinite. Habit of worm like that of form heretofore called by me Orygmatobothrium anguslum. Aug. 
12, 1900; numerous. Aug. 13, 1900; 106, young and adult, with numerous free, ripe proglottides. 
Dr. Dahlgren reports that many sand sharks have been opened this season (July-August, 1900) 
to supply material for work on cestodes in the Marine Biological Laboratory, and that this species has 
been found in great abundance in all of them. This species may lie identical with Tetrabothrium burha- 
tum Leidy. Fig. 235 is a sketch of the posterior end of a young strobile which appeared to be dividing 
into four by the abnormal enlargement of the lacinise. 
6. Bhynchobothrium longicorne Linton. Spiral valve. 2 , pp. 847-849, pl. in, figs. 4-8. 5, p. 450. 
Aug. 9, 1899; 4. 
7. Bhynchobothrium. Encysted in walls of stomach and intestine. 4 , p.798. Aug. 18, 1899; blastocyst 
from cyst in stomach wall. 
Isurus dekayi, Mackerel Shark. 
FOOD. 
One specimen, taken by the schooner Gram pur, July 30, 1900, had a conger eel and fragments of 
fish in the stomach. Entozoa collected by Mr. C. W. Stone, in formalin when examined. 
NEMATODES. 
1. Immature nematodes. Intestine. 
Few, small; length of largest, 12 mm. Same type frequently found in a great variety of fish. A 
diverticulum from base of proboscis and another from anterior end of intestine. 
CESTODES. 
2. Anthobothrium laciniatum Linton. Spiral valve. Not recorded before from Ibis host. See under 
Carcharinus obscuru-s, No. 3. 
These individuals, 5 in number, are smaller than specimens from the dusky shark. Dimensions 
in millimeters: Length, 5; breadth of head, 0.61 ; length of head, 0.34; diameter of neck, 0.09; distance 
of first segment from head, 0.36; last segment, length 0.58, breadth 0.43. 
3. Monorygma sp. Spiral valve. Twelve specimens, all very small and identical with No. 4, under 
Carcharinus milberti. 
The heads of the living worms were not seen, and it is difficult to determine the exact nature of 
the contracted specimens. There appears to be a myzorhynchus and the character of the acetabulum 
seems to be quite different from that of the species I have been erroneously calling Orygmatobothrium 
angustum. The auxiliary acetabulum of the latter resembles that of Crossobothrium and of Phyllobothrium. 
In the case of these specimens the auxiliary acetabulum is relatively larger than in the genera just 
named and appears to be simply the anterior part of the bothrium separated by a transverse partition. 
