Micronesian Gastropods — Demond 
289 
at Tomil Harbor, Yap. Morrison reports N. 
undata from the mangrove swamps along Bay 
of Islands, Fiji, living in the mud or on the 
mangrove roots together with Littorina 
scabra . 
geographic range: Widespread but ap- 
parently limited to the muddy shores of high 
volcanic islands and continental coasts and 
not found along the shores of atolls. USNM 
collections are from East Africa eastward 
through the Indian and Pacific oceans to the 
Tuamotu Islands, and from the Ryukyu Is- 
lands south to northern Australia and New 
Zealand. Uncommon in Micronesia and not 
reported at all from the Marshall, Mariana, 
Gilbert, or Hawaiian islands. 
Family LITTORINIDAE- Periwinkles 
Genus Littorina Ferussac, 1821 
Littorina coccinea (Gmelin, 1791) (syn. obesa 
Sowerby, 1832). 
Characteristically 0.5 to slightly more than 
1 inch long with a red-brown columella and 
aperture and without spiral lines within the 
aperture. Exterior light pink or purplish and 
entirely lacking additional color markings. 
Fig. 5. Littorina coccinea (Gmelin). Bikini Atoll, 
Marshall Islands (USNM 585874). 
Lives at and above high tide line along 
rocky shores, both ocean and lagoon, com- 
monly in groups in rock crevices. Frequently 
found in the zone barely wet by spray at high 
tide and even in areas wet only by rain. 
Morrison reports having found this species 
living as far as 50 to 100 yards inland. L. 
coccinea is characteristically active at night or 
on overcast days. 
geographic range: USNM collections 
are from Cocos-Keeling Atoll in the Indian 
Ocean eastward to the Hawaiian and Society 
islands, and from southern Japan south 
through Micronesia to Fiji. Reported from 
northern Australia. L. coccinea is the most 
common littorine in Micronesia. 
Littorina pintado (Wood, 1828). 
Hirase and Taki (1951) pi. 79, fig. 12; 
Tinker (1952) p. 174, 2 figs, on p. 175 
(poor). 
Characteristically 0.37 to slightly less than 
1 inch long with a dark brown columella and 
conspicuous dark brown spiral lines within 
the aperture. Exterior purplish gray and cov- 
ered with minute streaks or dots. 
Habitat similar to that of L. coccinea , al- 
though L. pintado apparently does not live as 
far above high tide line as does L. coccinea. 
According to Morrison and Cloud, the two 
species overlap in the upper spray zone, L. 
coccinea extending upward and L. pintado ex- 
tending down. Like most littorines, L. pintado 
can survive long periods of exposure. Ed- 
mondson (1946) reports an individual which, 
after being out of water for nearly a year, 
revived in a few minutes upon being replaced 
in sea water. 
geographic range: Uncommon in Micro- 
nesia, and apparently limited in its range to 
the northern Pacific islands. USNM collec- 
tions are from southern Japan, the Ryukyus, 
Bonins, Philippines (northern group only), 
Marianas, Marshalls, Johnston Island, and 
Hawaii. Reported from Formosa. 
Littorina scabra (Linne, 1758). 
Hirase and Taki (1951) pi. 79, fig. 13; 
Tinker (1952) p. 174, 3 figs, on p. 175. 
Characteristically 0.5 to slightly more than 
1.5 inches long and marked on all whorls with 
broad, brown zig-zag streaks. 
Lives at and above high tide line along 
muddy mangrove shores, either on the man- 
