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PACIFIC SCIENCE, Vol. XII, October, 1938 
while collecting the snail intermediate hosts. 
Cercarial dermatitis can be produced experi- 
mentally with C. liltorinalinae . 
Recently Gradhaus and Keh (unpublished 
data, 1957) reported cases of swimmer’s itch 
occurring on the beaches of the city of Ala- 
meda, bordering San Francisco Bay. Nassarius 
obsoletus , a marine snail intermediate host for 
A. variglandis on the Atlantic coast, was also 
the intermediate host in California. It was be- 
lieved that the snails were introduced into 
this area together with the oysters that had 
been planted in the bay. The schistosome 
cercariae from these snails were identified as 
those of A. variglandis. 
2. Hawaiian Islands 
Chu (1952) first reported the presence of a 
dermatitis-producing schistosome cercaria 
from the marine snail Littorina pintado Wood 
in two bird refuges on small offshore islands 
near Oahu, known as Bird Island (Moku 
Manu) and Rabbit Island (Manana). The 
snails infected with schistosomes were found 
only in the sea benches where there were 
many small tidal pools constantly receiving a 
sea spray. Collectors of the snails from the 
sea benches of Rabbit Island experienced 
itching and, in some cases, developed typical 
schistosome papule lesions on their feet. It 
may be added that the distribution of in- 
fectious cercariae seems to be limited to the 
bird refuges, because Chu and Cutress (un- 
published data, 1954) were unable to find 
schistosome-infected snails inhabiting any of 
the swimming beaches on the major islands 
of Oahu, Maui, Kauai, and Hawaii. The life 
history of this parasite has been reported by 
Chu and Cutress (1954). The natural defini- 
tive host for the adult stage was the ruddy 
turnstone (. Arenaria interpres interpres ), a shore 
bird which winters in the Hawaiian Islands. 
Chicks, ducks, and the sooty and noddy terns 
could be infected experimentally. 
After a study of the morphological char- 
acters of the adult stage of the schistosome in 
the naturally infected turnstones as well as in 
the experimentally infected animals, the au- 
thors concluded that this species was the 
same as the species of schistosome reported 
by Stunkard and Hinchliffe (1951, 1952) from 
the eastern United States along the Atlantic 
Ocean, i. e., Austrobilharzia variglandis. 
Penner (195 3^) reported that the red- 
breasted merganser (Mergus senator L.) was 
the natural definitive host for A. variglandis 
in the Atlantic coast. Munro (1944) states 
that this species of bird had been reported 
only as an occasional visitor to the Hawaiian 
Islands. However, Richardson and Fisher 
(1950) do not list the red-breasted merganser 
as a species found in the Hawaiian bird 
refuges. It can also be added that the western 
gull, a natural definitive host for A. littori- 
nalinae in California, is not a species generally 
seen on Oahu. 
The migration routes for shore birds in the 
Pacific Ocean have been studied by Baker 
(1951). On the basis of sight records, speci- 
men collection, known statistics of breeding 
and wintering, and from a study of maps of 
the region, he established the following three 
fly ways : (1) the Asiatic-Palauan, (2) the 
Japanese-Marianan, and (3) the Nearctic- 
Hawaiian. For each of the fly ways the author 
listed the names of the regularly visiting and 
the uncommonly visiting shore birds. Of the 
35 species mentioned, only the ruddy turn- 
stone and the golden plover ( Pluvialis do- 
minica fulva) were the ones common to all of 
the three fly ways. In the experience of the 
Hawaiian investigators, the golden plover was 
never found to be infected with the schisto- 
some, in contrast to the ruddy turnstone. 
King (1955) listed six major groups of sea 
birds found in the central Pacific Ocean. 
These are: (1) the albatrosses, (2) the shear- 
waters and petrels, (3) the terns, (4) the 
frigate birds, (5) the boobies, and (6) the 
tropic birds. Gulls and jaegers were listed as 
being occasionally seen. Chu and Cutress 
(unpublished data, 1954) did not encounter 
a single case of natural infection with schisto- 
somes in limited examinations of sea bird pop- 
