Micronesian Gastropods — Demond 
307 
monly a few feet below low tide line toward 
the reef edge. Occasionally found on lagoon 
reef flats. One specimen in the recent Micro- 
nesian collections was taken in 18 feet of 
water from the sandy lagoon slope of Ron- 
gelap Atoll. At Eniwetok, Morrison observed 
this species feeding on ceriths. 
geographic range: IJSNM collections are 
distributed from Mauritius eastward through 
the Indian and Pacific oceans to the Society 
and Marquesas islands, and from southern 
Japan south to Cocos-Keeling Atoll, the 
Caroline and Fiji islands. Common in Micro- 
nesia. Reported from Hawaii but not from 
Australia. C. chlorostomum also occurs in south- 
east Florida, the West Indies, and Bermuda. 
Cymatium (Lampusia) gemmatum (Reeve, 1844) 
(syn. mundum Gould, 1851).- 
Tinker (1952) p. 124, 2 figs, on p. 125. 
Characteristically 1.25 to 1.75 inches long. 
Shell white or whitish with a yellowish hairy 
periostracum and a white aperture and colu- 
mella. 
Found under rocks and coral on shallow 
reef flats, ordinarily just below low tide line 
on lagoon reef flats. 
GEOGRAPHIC range: USNM collections are 
from Cocos-Keeling Atoll in the Indian Ocean 
eastward through the Pacific to Hawaii and 
the Tuamotu Islands, and from southern 
Japan south to the East Indies, the Solomon 
Islands, and Fiji. Reported from Mauritius 
and northern Australia. Uncommon in Mi- 
cronesia. 
Subgenus Gutturnium Morch, 1852 
Cymatium ( Gutturnium ) muricinum Roding, 
1798 (syn. tuberosum Lamarck, 1822). 
Morris (1952) p. 184, col. pi. 6, fig. 1 [as 
C. tuberosum Lamarck]; Tinker (1952) p. 
124, 2 figs, on p. 125 [as C. tuberosum 
Lamarck]. 
Characteristically 1.75 to 3 inches long, 
with a slender, elongate anterior canal and a 
conspicuous columellar callus. Teeth, lips, 
and columella polished white. Aperture dark 
orange-brown within. 
Ordinarily lives in sandy lagoons, fre- 
quently a few feet below low tide line on 
lagoon shelves and lagoon reef flats, and to 
depths of 150 feet on lagoon floors. Also 
found on the deeper portions of seaward reef 
flats. 
GEOGRAPHIC range: USNM collections are 
from East Africa eastward throughout the 
Indian and Pacific oceans to the Hawaiian 
and Tuamotu islands, and from southern 
Japan south to New Guinea and New Cale- 
donia. Fairly common in Micronesia, but not 
reported from Australia. C. muricinum also 
occurs in southeast Florida, the West Indies, 
and Bermuda. 
Genus Charonia Gistel, 1848 
Charonia tritonis (Linne, 1758). 
Hirase and Taki (1951) pi. 95, fig. 9; Tinker 
(1952) p. 114, fig. on p. 115; Morris 
(1952) p. 185, col. pi. 6, fig. 9; Kira 
(1955) pi. 21, fig. 15. 
The largest member of the family Cyma- 
tiidae and one of the largest gastropods in the 
Indo-Pacific, commonly reaching up to 16 to 
18 inches long. 
Apparently lives on sandy bottoms of shal- 
low bays and lagoons, and in deeper water 
off the edge of seaward reefs. 
geographic range: USNM collections are 
from East Africa eastward through the Indian 
and Pacific oceans to Hawaii and Samoa, and 
from the Ryukyu and Mariana islands south 
to the New Hebrides and Fiji. Also reported 
from northern Australia and New South 
Wales. 
Family BURSIDAE-Frog Shells 
Genus Bursa Roding, 1798 
Bursa bubo (Linne, 1758) (syn. rubeta gigantea 
E. A. Smith, 1914). 
Tinker (1952) p. 120, fig. on p. 121 [as B. 
lampas Linne]. 
