DENTALIIDAE 



329 



Dentalium texasianum Philippi 



North Carolina and the Gulf States. 



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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„Om 



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. 



