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PACIFIC SCIENCE, Vol. XI, July, 1957 
The largest of the Trochidae, commonly 
with a basal diameter of 4 or 5 inches and a 
length of 3 to 4 inches. White with reddish, 
wavy, interrupted longitudinal streaks. 
Ordinarily lives in shallow water on rocks 
and in crevices near the outer edge of both 
seaward and lagoon reef flats. Also found on 
rocky bottoms, both ocean and lagoon, to 
depths of 40 or 50 feet. 
T. niloticus is the object of extensive fish- 
eries in Australia, Japan, the Palau, Philippine, 
Andaman, and Nicobar islands, because its 
shell is commercially valuable for manufac- 
turing buttons and jewelry and for inlaying 
and similar ornamental work. A detailed ac- 
count of its life history, habits, and habitat is 
presented by Rao (1939). The commercial 
use of the shell in the Philippines is discussed 
by Talavero and Faustino (1931). 
geographic RANGE: USNM collections 
are from Mauritius eastward to Fiji, and from 
southern Japan south to New Guinea and 
New Caledonia. Reported from northern 
Australia but not from Hawaii. Colonies of 
T. niloticus have been introduced at Truk, 
Yap, the Palau and Marshall islands. 
Trochus ochroleucus Gmelin, 1791- 
Characteristically 1.25 to 1.5 inches long. 
Resembles T. maculatus and T. histrio but may 
be recognized by its more massive shell, the 
short subsutural axial riblets on its body 
whorl, the raised spiral cord on its columella, 
and the absence of a red columellar blotch. 
Specimens are commonly encrusted with cor- 
alline algae, vermetids, and Foraminifera. 
Fig. 2. Trochus ochroleucus Gmelin. Kikaigasima, 
Osumi, Japan (USNM 343138). 
Lives under rocks and among coralline 
algal heads at the edge of reef flats, in the 
zone of breaking surf. Records in the recent 
Micronesian collections indicate that T. ochro- 
leucus lives in greatest abundance on windward 
reefs, both ocean and lagoon, although a few 
specimens were taken from leeward ocean 
reefs. T. ochroleucus is invariably found below 
low tide line. 
GEOGRAPHIC RANGE: Apparently limited to 
the Pacific. USNM collections are from south- 
ern Japan, the Ryukyu, Bonin, Mariana, 
Caroline, Admiralty, Marshall, Gilbert, Solo- 
mon, Loyalty, and Fiji islands, Samoa, Niau- 
fou, and New Guinea. Fairly common in 
Micronesia. Not found in Hawaii. 
Family TURBINIDAE -Turban Shells 
Genus Turbo Linne, 1758 
Turbo argyrostoma Linne, 1758. 
Hirase and Taki (1951) pi. 73, fig. 4. 
Characteristically 1.75 to 3.5 inches long. 
Recognized by its papillose, brownish or 
greenish operculum and the low scaly spines 
on its spiral ribs. 
T. argyrostoma lives in rock crevices on sea- 
ward reef flats, along the seaward reef edge, 
in rocky passes between reefs, and in crannies 
on minor reef prominences in lagoons. It 
invariably occurs below low tide line, com- 
monly in several feet of water. 
geographic range: USNM collections 
are from Aldabra Island and Mauritius in the 
Indian Ocean eastward through the Pacific 
to the Society and Tuamotu islands; and from 
southern Japan, the Ryukyu and Bonin is- 
lands south to New Guinea and New Cale- 
donia. Reported to be common in Queens- 
land, Australia. It is the most common Turbo 
in Micronesia. 
A form or subspecies of T. argyrostoma , 
characterized by a tendency toward chan- 
nelled sutures, swollen whorls, and a lack of 
spines, is common in Hawaii, although typi- 
cal T. argyrostoma is not found there. This 
