1898.] NATURAL SCIENCES OF PHILADELPHIA. 473 



ture has degenerated to a series of very small denticles. For the 

 rest, the form is fuller than any other known Macrodontes. 



A specimen from Cubatad, Sao Paulo, differs from the type in 

 being darker colored, of a dark reddish-chestnut hue, somewhat 

 more solid, with the denticles on the outer lip and columellar mar- 

 gin subobsolete, hardly noticeable, and of the reddish color of the 

 lip itself; the pits behind the lip are correspondingly obsolete, but 

 there are two minute white denticles on the columellar fold. This 

 shell measures: alt. 26, diam. 10 mm.; length of aperture 11, width 

 6$ mm. 



Odontostomus (Macrodontes) degeneratus n. sp. 



Shell oblong-turreted, minutely perforated, thin but moderately 

 strong, pale yellowish-green tinted. Surface hardly shining, striated 

 in the direction of growth-lines, the striae hardly visible without the 

 aid of a lens, under which they are seen to be thread-like, well 

 raised, finely but rather superficially cut into beads by decussating 

 spirals which crenulate the summits of the striae. Spire convexly 

 conic, the apex obtuse ; whorls nearly 6, quite convex, the earlier 1? 

 densely spirally striated, the last whorl becoming free and someAvhat 

 descending in front, constricted and showing 3 small pits behind the 

 outer lip, bicarinate at base, the keels short, outer one strongly 

 pinched up, the inner low, rounded, a distinct depression between 

 them. Aperture oblique, quadrangular-oblong, nearly i the total 

 length of the shell, obstructed by a strong columellar fold which 

 terminates below in a transverse lamella, and by 6 small, tuberculi- 

 form teeth : one upon the parietal margin close to its posterior 

 termination, three upon the outer lip, the uppermost quite small, 

 and with the parietal denticle, defining a small rounded posterior 

 sinus or notch, the others low, removed from the lip-edge; basal 

 tooth median ; columellar tooth below the columellar fold. Peri- 

 stome white, narrowly reflexed, continuous and free throughout. 

 Alt. 21, greatest diam. 8 - 3, length of aperture 7 mm. 



Palmeiras, Province of Parand, Brazil (Dr. H. von Ihering). 



The species here described differs so widely from all other known 

 species of the group, that detailed comparisons are needless. 



Odontostomus (Plagiodontes) Iheringi Pilsbry & Vanatta, n. sp. 



Shell deeply rimate, pupiform with conic spire, rather solid, light 

 olivaceous brownish with darker longitudinal streaks; somewhat 

 shining, sculptured with fine, irregular growth-strise. Last whorl 



31 



