12 DENTALIUM. 



decussated by very minute transverse strise. Apex entire. Length 

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



Gulf of Suez (Mac Andreyv). 



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 J ouss. 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 stride. 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 |, base H line (Bra- 

 zier). 



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

 Exped.). 



D. robxistum Braz., P. L. S. N. S. W., ii, p. 56 (1877). 



