102 DENTALIUM-L^VIDENTALIUM. 



D. ECOSTATUM Kirk. PI. 18, fig. 13. 



Shell white, nearly straight, smooth, gradually tapering, faintly, 

 distantly, transversely striated. Length 0*6, breadth at anterior 

 end 0*07 inch == 15, 1'75 mill. (Kirk). 



Waikanae, New Zealand (Kirk) ; also Pliocene of N. Z. at Wan- 

 ganui and Petane (Hutton). 



D. ecostatum KIRK, Ann. Mag. Nat. Hist. (5), vi, p. 15 (July, 

 1880) ; Trans. N. Z. Institute, xii, p. 306 (May, 1880). HUTTON, 

 Macleay Memorial Volume, p. 80, pi. 8, f. 79. 



Shell small, slightly curved, quite smooth, polished (Hutton). 

 The illustration is from Button's figure of a Pliocene specimen. 



D. LEBRUNI Mabille & Kochebrune. 



Shell rather straight, slightly curved toward the apex, white, 

 polished, opaque and solid ; at the base rapidly increasing ; apex 

 entire, neither slit nor emarginate. Length 75, greatest diam. 10 

 mill. (M. & #.). 



Santa Cruz, Patagonia (Lebrun). 



D. lebruni MAB. & KOCH., Miss. Sci. Cap Horn, vi, Zool., Moll., 

 p. 99 (1889). 



A nearly straight shell, only toward the apex a little arcuate ; 

 white, polished, without strise except at the base, where they are 

 quite perceptible. This species somewhat resembles D. lubricatum 

 Sow. of the coast of Australia, but it is larger, narrower, decidedly 

 less curved, and thinner at the summit (M. & J2.). 



Group of D. matara. 



Smooth and polished, elongated species, circular or subcircular in 

 section, with the apical characters of typical Antalis or of Fissiden- 

 talium a V-shaped notch or a slit. 



Those who attach cardinal value to the modifications of the apex 

 would place most or all of these forms in Antalis (Entalis or Entali- 

 opsis'j. They have a more or less projecting rim or sheath around 

 the anal orifice, interrupted by a slit or V-shaped notch on the con- 

 vex side. In including the group under Lcevidentalium, we empha- 

 size rather the smooth surface ; but neither course is entirely satis- 

 factory to us. 



Key to Species. 



I. Shell much curved throughout, amber, earn elian or white, aper- 

 ture circular; length about 90 mill., about 19 times the diam., 



longitrorsum, p. 111. 



