2 DENTALIUM. 



its edge excavated within and slightly notched excentrically on the 

 convex side (fig. 6). Length 70, diain. at aperture 11-5X11 mill.; 

 height of arch above chord 15"5 mill. 



Amboyna (Rumphius) ; Philippine Islands (Phil. Acad. Coll.). 



D. elephantinum Linn., Syst. Nat. (10;, p. 785 (1758) ; Ibid (12), 

 p. 1263 (17G6).— Gmel., Ibid (13), p. 3736 (1788).— Lam., Syst. 

 An. s. Vert., p. 326 (1801); Anim. s. Vert., v, p. 343 (1818).— 

 Wood, Index Testae, p. 183, No. 2 (1818).— Sowb., Thes. Conch., 

 iii, p. 102, pi. 223, f. 4 (1860) ; and in Reeve, Conch. Icon,, xviii, 

 pi. 1, f. 5.— Chenu, Illustr.Conchyl., pi. 1, f. 4-10.— Hanley, The 

 Shells of Linnaeus, p. 435. — Sowb., The Genera of Shells, Dentalium, 

 f. 1 ; Zool. Jour., iv, p. 196. Not D. elephantinum ^rocchi, Conch. 

 Foss. Subapp., ii, p. 260 (1814), nor of Philippi, Enum. Moll. Sicil., 

 i, p. 245 ; ii, p. 206, nor of Desh., 1825, nor of Risso, 1826, p. 399. 

 See D. dslessertianum Chenu. 



D. arcuatum Gmel., Syst. Nat. (13), p. 3738 (1788).— Anton, 

 Verzeich., p. 25. — D. elephantium Born, Mus. Cses. Vindob., p. 431. 

 — ? D. recurvum Da., (by error ?), Monogr. Dent., p. 30. — D. striatum 

 (in part) Born, 1. c, p. 431. 



A well known species, well distinguished by its robust form, green 

 color and (usually) ten strong ribs. The apical orifice often has a 

 slight rim, as in D. entalis ; and the short notch is situated between 

 two of the ribs a little aside from the median line of the convex 

 side. 



D. FORMOSUM Adams & Reeve. PI. 1, figs. 9, 10, 11. 



Shell arcuate, rather tumid, 13-ribbed, the ribs rounded, inter- 

 stices rather wide. Anal end slit, the slit on the convex side, wider 

 toward the apex. Very beautifully variegated with rose, olive-green 

 and white {A. & R.). Length 60, greatest diam. 13*5 mill, (from 



fig.). 



Sooloo Archipelago, outside a coral reef near the city of Sooloo, 

 in about 16-20 fms., sandy mud (Adams). 



D. formosum A. & R., Zool. H. M. S. Samarang, Moll., p. 71, pi. 

 5, 11 a, b (1848).— Sowb., Thes. Conch., iii, p. 102, pi. 223, f. 2 

 .(I860).— Sowb. in Reeve, Conch. Icon., xviii, pi. 2, f 7 (1872). 



Of rather lighter and more tumid growth than D. elephantinum, 

 richly variegated with rose, olive-green and a little white. Sow- 

 •erby figures and describes it as with 15 ribs. 



