26 SPIEAXIS. 



22. S. RHOADS^ (Pitebry). PI. 2, figs. 21, 22. 



Shell slender, subulate, imperforate, corneous, and suffi- 

 ciently translucent to show the internal axis through the shell 

 in places. Surface glossy, sculptured with unequally spaced 

 longitudinal grooves, and showing a few slight growth- 

 wrinkles in places. General outlines of the spire straight. 

 Apex obtuse. Whorls 9 to 9y 2 , the earlier ones quite convex, 

 the later four or five somewhat flattened. Aperture small, 

 ovate, the outer lip a trifle curved forward in the middle ; 

 columella slender, concave. 



Length 7, diam. 1. 9, longest axis of aperture 1.6 mm. 



Length 7, diam. 1.7, longest axis of aperture 1.6 mm. 



Mexico: Diente, near Monterey, State of Nuevo Leon 

 (Mr. and Mrs. Rhoads). 



Opeas rlwadsff PILS., Proc. A. N. S. Phila. 1899, p. 399; 

 1903, p. 775, pi. 50, f. 4. 



Similar in sculpture and color to S. odiosus, but perceptibly 

 more slender in the spire, with smaller apex. These two 

 species have the general form of Opeas gracile, but differ 

 totally in sculpture ; they are also more brilliant and more 

 transparent. The columella is not at all twisted, and there is 

 no trace of a basal notch or truncation. This species, of which 

 about fifteen specimens were obtained, is named in honor of 

 Mrs. Mary C. Rhoads. 



23. S. PATZCUARENSIS (Pilsbry). PI. 2, fig. 23. 



Shell minute, imperforate, subcylindric, very slowly taper- 

 ing to the obtuse summit, whitish-buff. Surface glossy, 

 smooth except for rather widely spaced, rather inconspicuous 

 longitudinal grooves. Whorls 7%, the early ones quite con- 

 vex, later whorls moderately so, the last tapering basally. 

 Aperture irregularly ovate, nearly vertical, the outer lip 

 curving forward a little. Columella vertical in front view, 

 but convex in the middle when viewed obliquely in the aper- 

 ture. Length 3.1, diam. 1 mm., aperture .7 mm. long. 



Mexico: Patzcuaro, State of Michoacan (Rhoads). 



Opeas patzcuarcnse PILS., Proc. A. N. S. Phila, 1899, p. 

 399; 1903, p. 775, pi. 50, f. 5. 



