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Dentalium texasianum Philippi
North Carolina and the Gulf States.
DENTALIIDAE 329
Texas Tusk
Figure 69c
% to I % inches in length, thick-shelled, well-curved, hexagonal in cross-
section and dull, grayish white in color. The broad spaces between the ribs
are flat. Common from 3 to 10 fathoms. The subspecies cestum Henderson
from Texas has numerous, cord-like riblets between the six main ribs.
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Figure 69. Tusk Shells, a, Cadiihis carolmensis Bush, % inch (southeast United
States), showing an enlargement of the apical end; b, apical end of Caduliis qiiadri-
dentatiis Dall, % inch (southeast United States); c, Dentalium texasiamnn Philippi,
I inch (southeast United States), showing cross-section at each end; d, cross-section
of D. pilsbryi Rehder, i inch (west Florida); e, D. eboreum Conrad, 2 inches
(southeast United States); f, D. pretiosiim Sowerby, 2 inches (Pacific Coast).
Subgenus Dentale Da Costa 1778
Dentalium entale stimpsoni Henderson Stimpson's Tusk
Nova Scotia to Cape Cod, Massachusetts.
I to 2 inches in length, round in cross-section and dull, ivory-white in
color. Region of the apex always very eroded and chalky. Surface uneven
and with some longitudinal wrinkles in better preserved specimens. A poor
subspecies of the north European D. entale Linne. Common from 8 to 1 200
fathoms. The subgenus Antalis H. and A. Adams is the same as Dentale.
Dentalium occidentale Stimpson Western Atlantic Tusk
Newfoundland to off Cape Hatteras, North Carolina.