12 DENTALIUM. 



decussated by very minute transverse striae. Apex entire. Length 

 1-75, breadth at base 0'25 inch (Cooke). 



Gulf of Suez (Mac Andrew). 



D. Uneolatum COOKE, Ann. Mag. Nat. Hist. (5) xvi, p. 274 

 (Oct., 1885). 



In fresh specimens the interstitial lines are very marked ; they 

 are parallel to the ribs, which are themselves generally bisected by 

 a similar line (Cooke). 



D. laugieri Jouss. and D. reevei Desh. seem to be identical with, or 

 at least very nearly allied to, this species. Although reevei has pri- 

 ority, the absence of a sufficient description would lead us to adopt 

 Cooke's name should the specific identity of these forms be confirmed. 

 The descriptions here follow : 



D. laugieri Jousseaume. Shell white, solid, cylindrical, slightly 

 arcuate, longitudinally costate ; ribs 9, equal, strong, rounded, 

 smooth ; the intervals flat, wider, with 3 to 5 delicate striae. Length 

 40-48, diam. 7 mill. (Jouss. in Bull. Soc. Philomath, de Paris, 

 (8), vi, p. 103, 1894). 



Aden ; Suez. 



This form seems to present no tangible differences from D. Uneo- 

 latum Cooke, and from comparison of the diagnoses we believe it a 

 synonym. 



D. reevei "Deshayes" Fischer. This species, which will shortly 

 be described by M. Deshayes, is white, arcuate, having 9 longitudi- 

 nal ribs. The interstices are very finely striated transversely, and 

 some longitudinal narrow ribs run along them. (D. reevei De- 

 shayes, mss., Fischer, Journ. de Conchyl., xix [(3), xi], p. 212, 

 1871). 



Suez. 



The above insufficient descriptive note is all that has been pub- 

 lished on this species. Compare D. laugieri Jouss. and Uneolatum 

 Cooke, with which reevei is probably identical. 

 D. ROBUSTUM Brazier. 



Shell nearly straight, thick, dull white, longitudinally 9-ribbed, 

 ribs rounded, wide apart, narrow toward the apex, interstices flat- 

 tened, smooth ; apex with small perforation, entire ; aperture thick- 

 ened, regular. Length 10 lines, diam. of apex f, base 1 \ line (Bra- 

 zier). 



Katow, New Guinea, 8 fathoms, sandy mud and coral (Chevert 

 Exped.). 



D. robmtum BRAZ., P. L. S. N. S. W., ii, p. 56 (1877). 



