44 SP1RAXIS. 



whorl, when it is sufficiently transparent, or by observing 

 broken shells, that the spiral trend of the axis becomes ap- 

 preciable. 



46. S. UNUS Pilsbry, n. sp. PL 3, fig. 40. 



Shell very thin, clear corneous, glossy, with even, regular 

 and close sculpture of arcuate longitudinal grooves separ- 

 ated by flat intervals, about 12 in the space of 1 mm. on the 

 front of the last whorl. First 1% whorls smooth. Whorls 

 4%, strongly convex just below the deeply cut suture, but 

 elsewhere flattened'. Aperture narrowly piriform; outer lip 

 arched forward in the middle. Columella very short and ver- 

 tical 'as seen from in front, but somewhat convex in the 

 middle in oblique view; sinuous as seen through the shell. 

 Length 4.24, diam. 1.4, length of aperture 1.8 mm. 



Haiti: Thomazeau (J. B. Henderson). 



The unique example of this species is smaller and more 

 slender than S. verberatus, but with about the same number 

 of whorls. The sculpture is similar but finer. 



Subgenus GLANDINELLA Pfeiffer. 



Glandinella PFR., Nomenclator Heliceorum Viventium p. 

 328, 1878, for B. poeyanus. 



Shell imperforate, subulate-turrite, composed of about 8 

 rather rapidly widening whorls. First 1% whorls smooth, 

 the next whorl delicately closely striate, the rest of the Whorls 

 sculptured with spaced riblets and marked with dark varix- 

 streaks. Aperture long-pirifoTm, its length fully twice the 

 width; outer lip simple, arched forward; columella concave 

 below, ascending in & long weak spiral. Soft anatomy un- 

 known 1 . 



Distribution, Isle of Pines. Type S. poeyanus. 



The embryonic shell (pi. 3, fig. 38) seems to be composed 

 of 2% whorls. The first iy 2 are smooth, and increase very 

 rapidly; then the width of the whorl from suture to suture 

 decreases slightly, and close, fine, vertical striae begin. This 

 stage continues three-fourths of a whorl, and there abruptly 



