134 
PACIFIC SCIENCE, Vol. XII, April, 1958 
units. In this connection these records, es- 
pecially of Monogenea which are host speci- 
fic, are of interest. Capsala biparasitica from 
yellowfin tuna in Japan and the Line Islands, 
Hexastoma grossum from bigeye in Japan and 
the Line Islands, Neothoracocotyle acanthocybii 
from wahoo in the Line and Galapagos is- 
lands, and Capsala poeyi from the black marlin 
in the Atlantic and Pacific, all suggest that 
these stocks of fish are not, or were not, com- 
pletely independent. 
Fig. 2. Didymocystis acanthocybii. (A) Photomicro- 
graph of a cross section through two trematodes show- 
ing the host tissue (W) surrounding the cyst, the 
forebodies (F), the hindbodies (H), the uterus (U), 
and vitellarium (V) of each. (B) Photomicrograph of 
a section through two trematodes showing the forebody 
of one in sagittal section. 10 microns. 
REFERENCES 
Edmondson, C. H. 1946. Reef and Shore Fauna 
of Hawaii. Bernice P. Bishop Museum 
Special Publication 22, iv + 381 pp. 
Goto, S. 1894. Studies on the ectoparasitic 
trematodes of Japan. Tokyo Imp . Univ Col. 
Sci. Jour. 12(4): 263-295. 
Hargis, W. J., Jr. 1956. Monogenetic trema- 
todes of Gulf of Mexico fishes. Part XII. 
The family Gastorcotylidae Price, 1943. 
Bui. Mar . Sci. Gulf and Caribbean 6(1): 
28-43. 
I shii, N., and T. Sawada. 1938. Studies on 
the ectoparasitic trematodes. Livro Jub. 
Lauro Travassos. Pp. 231-243. Rio de 
Janeiro. 
Iversen, E. S., and H. O. Yoshida. 1957. 
Notes on the biology of the wahoo in the 
Line Islands. Pacific Sci. 11 (4):370-379. 
King, J. E., and I. I. Ikehara. 1956. A com- 
parative study of the food of bigeye and 
yellowfin tuna in the central Pacific. U. S. 
Fish and Wildlife Ser., Fishery Bui. 57(108): 
61-85. 
Kishinouye, K. 1923. Contributions to the 
comparative study of the so-called scom- 
broid fishes. Tokyo Imp. JJniv., Col . Agr. 
Jour. 8(3): 293-475. 
Manter, H. W. 1955. The zoogeography of 
trematodes of marine fishes. Expt. Parasi- 
tology 4(1): 62-86. 
Metcalf, M. M. 1929. Parasites and the aid 
they give in problems of taxonomy, geo- 
graphical distribution, and pa leogeo graphy .. 
Smithsn. Inst., Misc. Collect. Vol. 81, No. 8. 
36 pp. 
Nigrelli, R. F., and H. W. Stunkarb. 1947. 
Studies on the genus Hirudinella , giant 
trematodes of scombriform fishes. Zoologica 
31(13): 185-196. 
Vigueras, I. 1935. Tristomum poeyi n. sp. 
(Trematoda), parasito de Makaira ampla 
Poey (Pisces). Nat. Hist . Soc. Cuba , Mem. 
9(1): 43-44. 
Yamaguti, S. 1938. Studies on the helminth 
fauna of Japan. Part 21. Trematodes of Fishes, 
IV. 139 pp. Maruzen Co., Tokyo. 
