PARASITES OF FISHES OF THE WOODS HOLE REGION. 
427 
CESTODES. 
2. Dxscocephalum pileatum Linton. Spiral valve. 2 , pp. 781-787, pi. x, figs. 1-7. 7 , p. 272. Rare; 
heads buried in mucous membrane of spiral valve; difficult to remove without breaking. 
3. Anthobothrium ladniatum Linton. Spiral valve. 2, pp. 754-759, pi. in, figs. 10-13, and pi. iv, figs. 
1-3. 7 , p. 272. July 17, 1899; from one host, 1. July 22, 1899; from one host, 1. Aug. 1, 
1899; from one host, 150. Aug. 21, 1899; from one host, 53. Aug. 25, 1899; from one host, 
numerous. July 20, 1900; from one host, 7. 
4. Crossobothrium anguslum Linton. [ Orygmatobothrium angustum Linton.] Spiral valve. 1, pp. 
468-469, pi. in, figs. 1-3. 2 , pp. 796-799, pi. vn, fig. 3. 7 , p. 272. July 22, 1899; from one 
host, 11. Aug. 1, 1899; from one host, 12. Aug. 25, 1899; from one host, 3. July 20, 1900; 
from one host, 24. 
Among the specimens collected in 1900 two types were represented, one elongated, very slender, 
almost hair-like, attaining a length of 30 mm. with elongated and squarish segments; the other much 
shorter with moniliform segments beginning 10 mm. back of head. The generic name Orygmatoboth- 
riwrn must be discontinued for this form. It and Crossobothrium , probably, are generically the same — 
i. e., bothria cruciforinly arranged, each with a single auxiliary acetabulum. The latter does not 
resemble anterior end of bothrium of Monorygma. Of frequent occurrence, sometimes abundant. 
5. Phoreiobothrium lasium Linton. Spiral valve. 1 , pp. 474-476, pi. iv, figs. 24-29. 2 , pp. 819-820. 
7 , p. 272. Aug. 11, 1899; from one host, 50. Aug, 21, 1899; from one host, 146. Aug. 25, 1899; 
from one host, numerous. July 20, 1900; from one host, 3. 
6. Phoreiobothrium triloculatum sp. nov. Spiral valve. [PI. xxvi, fig. 292.] Aug. 11,1899; from one 
host, 10. Aug. 25, 1899; from one host, few. July 20, 1900; from one host, 16. 
Head larger than that of P. lasium. The most striking difference is in the posterior ends of 
bothria, each of which has three loculi (arranged in a transverse row) instead of the numerous small 
loculi characteristic of P. lasium. Dimensions of a specimen in sea water, in millimeters: Length, 25; 
length of head, 0.71; breadth of head, 0.76; thickness of head, 0.63; breadth of neck, 0.36; thickness 
of neck, 0.13; distance to first distinct segment, 4.5; length of last segment, 3; breadth, 0.78. 
7. Platybotlirium cervinurn Linton. Spiral valve. 2, pp. 820-823, pi. vm, figs. 8-10, and pi. ix, fig. 1. 
8. Tetrarhynchus bisulcatus Linton. 1 \Rhynchobothrivm bisulcatum], pp. 479-486, pi. iv, figs. 9-23. 
2, pp. 857-861, pi. xiv, figs. 10-12, and pi. xv, fig. 1. 5, p. 452. 7, p. 272. Sometimes very 
abundant in the pylorus, the heads often embedded in the mucous membrane. 
9. Telrarliynchus bicolor Bartels. 4 , pp. 813-815, pl.Lxvm, figs. 5, 6. 
10. Tetrarhynchus sp. Cysts, stomach wall. 4 , pp. 807-808. 
11. Cysts containing degenerate connective tissue sometimes found in the walls of alimentary tract. 
TREMATODES. 
12. Gasterostomum areuatum Linton. Spiral valve. July 22, 1899; from one host, 5 larger, with ova, 
3 smaller. 
Length of larger, 3.29 mm., very changeable, especially the anterior part. Translucent white 
except back of middle where the color is yellow on account of the ova. The alcoholic specimens are 
arcuate; their slender necks densely clothed with flat spines, which continue to the posterior end. 
On the posterior half of the body they are less dense and arranged in transverse series. OvaO.021 and 
0. 014 mm. in the two principal diameters. These specimens agree with those from the bonito in all 
essential characters. The only point of difference noted is that the number of vitellaria does not appear 
to be quite so definite in these as in the specimens from the bonito. Their arrangement, however, is 
the same, and the number does not vary greatly from that given in the original description, viz, 32. 
See 7 , pp. 297-298, pi. xli, figs. 85-90. 
Sphyrna zygsena, Hammerhead. 
FOOD. 
Fish and squid. 
NEMATODES. 
1. Spiroptera pectinifer sp. nov. Stomach. [PI. xv, figs. 197, 198; pi. xvi, fig. 199.] 
Two nematodes, a male and a female, collected July 18, 1887, are here recorded. Mouth terminal, 
aperture round, two small lateral papillae on head. Tail in each coiled in a close spiral. Siiicules in 
