TORNAXIS. 219 



below, obliquely truncate, covered with a rather thick white 

 callus which joins the lip above. Outer lip projecting in the 

 middle, deeply sinuated above, slightly thickened below the 

 sinus. Length 5.5, dram. 1.33, aperture 1.33 x 1 mm. 

 (Smith). 



Trinidad (J. H.' Ponsonby) . 



Luntia insignis SM., Journ. of Conchology ix, p. 28, fig. 

 8 (Jan. 1898). 



"The slender costae being produced above, give the suture 

 a crenulated appearance, and below, as a rule, they do not 

 extend quite across the whorls. The columellar callus is very 

 thick, the upper part almost forming a tubercle " (Smith). 



Genus TORNAXIS von Martens. 



Biologia Centrali Americana, Mollusca, p. 311 (April, 

 1898), for T. singularis. 



1 i Shell turrite, imperf orate, vertically costulated, not shin- 

 ing, many-whorled, not keeled ; aperture ovate, external mar- 

 gin simple, arcuate; columellar margin very thick, strongly 

 twisted, separated by a deep and narrow notch from the 

 basal margin. Anatomy not yet known. 



"This genus possesses to a certain extent the characters 

 of both Subulina and Spiraxis as regards the form of the 

 aperture, but in its general aspect it approaches nearer to 

 Rhodea H. & A. Adams, from which it only differs in the 

 absence of the prominent spiral keel in the terminal whorls. 



Named from axis, and tornare, to turn on a lathe ; analog- 

 ous to Spiraxis" (v. Mts.). 



This genus resembles Luntia in its thick columellar callus, 

 notched base and costulate surface, but differs by the simply 

 arcuate outer lip, not deeply sinuate above. Soft anatomy 

 and embryonic whorls unknown. 



1. T. SINGULARIS Martens. PL 40, fig. 16. 



"Shell cylindrically turrite solid, with vertical narrow 

 costge, separated by interstices which are from two to four 

 times a& broad as the costse, of dull greenish color. Whorls 

 very convex, with simple linear sutures, six in number in the 

 only specimen obtained, which is broken above (there are, 



