SYNAPTERPES. 233 



oblique, acuminate above, narrowed below; outer lip thin 

 and simple, not perceptibly arched forward. Columella sub- 

 vertical, not reaching the base. There is an oblique fold be- 

 low, causing it to be obliquely truncate basally; the colu- 

 mellar margin is reflexed. Length 25, diam. 8.7, aperture 

 9 mm. 



Colombia: Marmato (T. Bland). 



Closely related to S. auratus Pfr., but having more whorls 

 in a smaller shell, a smaller aperture and more distinctly 

 truncate columella. The structure of columella and um- 

 bilicus is the same in young shells 7 mm. long as in those 

 of 25 mm. 



7. S. BISTORTUS (Pfeiffer). 



Shell imperforate, turrite, rather thin, lightly arcuate- 

 striate, glossy, pellucid, olive-corneous; spire elongate, sub- 

 rectilinear, obtuse ; suture lightly impressed, obsoletely cremi- 

 late ; whorls 11, rather flattened, the last one-fourth the total 

 length, tapering basally, pale. Columella having two 

 twisted, thread-like folds. Aperture oblique, oval-oblong; 

 peristome simple, unexpanded. Length 38, diam. 8, aper- 

 ture 9x4 mm. (Pfr.}. 



Habitat unknown (coll. Cuming). 



Spiraxis bistort a PFR., P. Z. S. 1854, p. 293; Monogr. 

 iv, p. 573. 



An unfigured species, noticed by no later author. A 

 somewhat similarly two-plicate columella has been found in 

 the African Subnlina columcUaris Martens (see p. 90). Its 

 systematic position is uncertain. 



Subgenus ZONIFERELLA Pilsbry, 1906. 



Shell glossy, greenish-black with a white peripheral band; 

 columella reflexed, Bulimoid. Oviparous. Type S. albo- 

 balteatus. 



The apical whorls have not been described. 



8. S. ALBOBALTEATUS (Dunker). PI. 37, figs. 97, 98. 



Shell small, thin, oblong-ovate, subfusiform, slightly rim- 



