226 SUBULINA. 



delicate plication below the suture. Spire straightly taper- 

 ing, the summit obtuse. Whorls 6%, convex, parted by a 

 delicately crenulate suture. Last whorl weakly subangular 

 at the periphery. Aperture ovate, slightly oblique. Outer 

 lip thin and sharp as usual. Columella concave above,, ob- 

 liquely truncate near the base, sigmoid in an oblique view 

 in the mouth. Length 9, diam. 3, aperture 2.8 mm. 



Brazil: twenty miles below Para. Cotypes in coll. A. N. 

 S. P. and J. Ritchie, Jr. 



This species is closely related to S. octona but differs con- 

 stantly by its closely, finely striate surface, somewhat re- 

 sembling the West African forms. It probably attains a 

 greater size. 



5. S. POREECTA Martens. PI. 39, figs. 23, 24, 25. 



Shell imperforate, cylindric-subulate, rather solid, lightly 

 striatulate, yellowish-waxen, moderately glossy, unicolored, 

 the apex globular. Whorls 9%, the upper ones a little con- 

 vex, the lower flattened, slightly wider than high, the last 

 whorl higher than wide, gradually tapering basally. Aper- 

 ture long-ovate, the columellar margin slightly con'cave, very 

 obliquely truncate towards the base. Length 21 to 25, diam. 

 4.5 to 5, aperture 4.5 x 2 to 4.66 x 2.5 mm. (Marts.). 



Mexico: Teapa, State of Tabasco ( H. H. Smith). 



S. porrecta MARTS., Biologia p. 300, pi. 17, f. 14 (April, 

 1898) . S. trochlea in part, FISCHER & CROSSE, Miss. Sci. Mex., 

 Moll, i, p. 642, pi. 25, f. 14 (Yucatan). 



' ' Distinct from 8. octona and its variety trochlea chiefly by 

 the more, slender and less convex form of the last whorls, and 

 the scarcely concave columellar margin" (Marts.). 



6. S. CYLINDRELLA (Morelet) . PL 39, figs. 26, 27. 



Shell subulate-turrite, irregularly sculptured with distant, 

 not very conspicuous riblets, thin, hyaline, pale corneous. 

 Spire long, the apex obtuse, rounded; suture impressed. 

 Whorls 11, a little convex, the first two smooth, the last much 

 shorter than the spire, not one-fourth the total length, the 

 base nearly smooth, aperture subovate ; peristome simple, pale 

 corneous, the margins disjoined, columellar margin short, sub- 



