306 MEXICAN LEPTINARIA. 



duced when good series are available for comparison. Spir- 

 axis dubia Pfr. may, von Martens suggests, belong to Leptin- 

 aria, but it seems more nearly related to the Oleacinidce. 



No parietal lamella at any stage of growth, species 16 to 35. 



A parietal lamella developed at least in the young, species 

 36 to 40. 



L. imp erf or at a, no. 33, seems to be related to the long An- 

 tillean and South American species, rather than to those of 

 Mexico. 



17. L. TAMAULIPENSIS Pilsbry. PI. 50, fig. 26. 



Shell openly perforate, ovate-conic, pale yellowish-corneous. 

 Surface glossy, finely and closely, irregularly and weakly stri- 

 atulate, and showing very indistinct traces 'of spaced riblets 

 parallel to growth lines. Spire straightly conic, the apex 

 quite obtuse. Whorls 5 l / 2 , convex. Aperture less than half 

 the total length. Columella vertical, broadly reflexed above, 

 tapering downwards, obliquely subtruncate and having a low 

 fold slightly below the middle. No parietal lamella. Length 

 7, diam. 3.7 mm., aperture 3 mm. long. 



The young shells of 2.5 mm. length have a relatively 

 stronger columellar lamella than adults, tut no parietal ar- 

 mature. 



Mexico : Tamaulipas, in a canon about 4 miles west of 

 Victoria, elevation about 3,000 feet (Rhoads). Types 85,909, 

 A. N. S. P. 



L. tamaulipensis PILS., Proc. A. N. S. Phila., 1903, p. 776, 

 pi. 50, f. 8. 



This species is related to L. mexicana and L. martensi, but 

 differs from both in wanting spaced riblets, though faint 

 traces of them persist, at least in some specimens. They are 

 represented much too strongly in the figure. No other Lep- 

 tinaria has been reported from north of Misantla, Vera Cruz. 



18. L. MEXICANA (Pfr.). PI. 41, figs. 2, 3, 4, 5. 



Shell su<bperforate, ovate^turrite, rather thin, whitish-hya- 

 line; sculptured with rather distant, fine plicae. Spire ele- 

 vated, the apex obtuse. Whorls 7, convex, the last about 

 two-fifths the total length, rounded Nasally. Columella rather 



