Micronesian Gastropods — Demond 
287 
form has been called T. articulatus Reeve and 
T. inter costalis Menke. 
Turbo petholatus Linne, 1758 (syn. variabilis 
Reeve, 1842; militaris Reeve, 1848). 
Hirase and Taki (1951) pi. 73, fig. 1. 
Characteristically 1.25 to 3 inches long with 
a polished shell strikingly marked with red- 
dish-brown and fawn color. 
The recent Micronesian collections contain 
only two specimens of T. petholatus. Both 
were found living on small reefs on the sandy 
lagoon shelf at Ifaluk. These particular reefs 
are never exposed, even during spring tides, 
and are ordinarily covered by 3 to 5 feet of 
water at low tide. 
geographic range: USNM collections 
are from Mauritius in the Indian Ocean east- 
ward through the Pacific to the Society and 
Tuamotu islands, and from southern Japan 
south to northern Australia and New Cale- 
donia. Uncommon in Micronesia. Not found 
in Hawaii. 
Turbo setosus Gmelin, 1791 (syn. stenogyrus 
Fischer, 1873). 
Hirase and Taki (1951) pi. 73, fig. 5 [as 
T. stenogyrus Fischer]; Morris (1952) p. 
164, pi. 35, fig. 11. 
Characteristically 1.5 to 3.75 inches long. 
Distinguished from T. argirostoma by its typi- 
cally smooth, white operculum, its lower 
spire, and the absence of spines on its spiral 
ribs. 
T. setosus apparently lives almost exclusively 
on the seaward edge of windward ocean reef 
flats, embedded in rock crevices. It is also 
reported from the edge of the windward la- 
goon reef flat at Bikini where the lagoon is 
broad enough to allow the development of a 
strong surf along the windward lagoon shore. 
geographic range: Apparently limited to 
the Pacific. USNM records are from the Mari- 
ana, Marshall, Gilbert, Caroline, Solomon, 
Fiji, Samoan, Niaufou, Cook, Society, and 
Tuamotu islands, and from New Guinea. Re- 
ported from the Ryukvus, Philippines, For- 
mosa, and Queensland, Australia. Common 
in Micronesia but not as abundant there as 
T. argyrostoma. Absent from Hawaii. 
Family NERITIDAE— Nerites 
Genus Nerita Linne, 1758 
Nerita albicilla Linne, 1758. 
Hirase and Taki (1951) pi. 75, fig. 8; Morris 
(1952) p. 166, pi. 36, fig. 15; Kira (1955) 
pi. 11, fig. 15. 
Characteristically about one inch long with 
rows of tubercles on the columellar deck. 
N. albicilla is a solitary species found on or 
under rocks of seaward reef flats or along 
rocky ocean shores. None of the specimens 
studied were taken along lagoon shores. N. 
albicilla apparently lives near low tide line, 
farthet from shore than N. plicata , N. polita , 
or N. undata. 
geographic range: USNM collections 
are from the entire east African coast, includ- 
ing the Red Sea, eastward through the Indian 
and Pacific oceans to the Tuamotu Islands, 
and from southern Japan and Hawaii south 
to New South Wales, Australia. An uncom- 
mon species in Micronesia. 
Nerita plicata Linne, 1758. 
Hirase and Taki (1951) pi. 75, fig. 14; 
Tinker (1952) p. 198, figs, on p. 199; 
Kira (1955) pi. 11, fig. 17. 
Characteristically about one inch long with 
conspicuous raised spiral ribs, a wrinkled 
columellar deck, and four strong columellar 
teeth. 
N. plicata is typically found living in groups 
on and under rocks at and above high tide 
line along both ocean and lagoon shores. 
Although it is out of water for long periods, 
it apparently avoids desiccation by remaining 
in rock crevices during the day. At night it 
creeps about the rocks, presumably feeding 
upon surface algae. It is also frequently active 
on rainy or overcast days. N. plicata is com- 
monly associated with species of Littorina and 
Melampus. 
