228 SYNAPTERPES. 



Shell riniate or imperforate, ovate-turrite, thin, glossy, 

 composed of 7 or 8 whorls, which are crenulated below the 

 sutures, the embryonic whorls smooth, summit obtuse but not 

 bulbous, with a comma-shaped apical dimple. Aperture 

 long-ovate, with thin, sharp outer lip ; columella slender, 

 strightened above, broadly concave below, not truncate, its 

 edge narrowly reflexed above. Type S. hanleyi. 



The soft anatomy is not known, with certainty. Mr. W. 

 G. Binney has described the jaw and teeth of hanleyi and 

 figured the latter, as similar to Strophocheilus ; but the con- 

 chological features of the snail are so at variance with this 

 result that I am disposed to think that some misidentification 

 or inadvertent exchange of radula? in mounting may have 

 occurred. 



The genus differs from Obeliscus by its long-ovate shape, 

 smaller number of whorls, and deeper apical dimple. The 

 shell unites the Bulimoid form and the Stenogyroid texture. 



The genus is somewhat heterogeneous, but I feel that 

 little progress can be made towards a more natural group- 

 ing until we have more knowledge of the South American 

 fauna. The following subgenera may for the present be 

 recognized. 



SYNAPTERPES s. str. Embryonic shell smooth; aperture 

 Bulimoid, the columella entire below. Species 1-3. 



PROMOUSSONIUS. Embryonic whorls large and arcuately 

 rib-striate, the rest decussate; columella, entire. Species 4. 



CHRYSERPES. Embryonic whorls smooth; columella with 

 a small spiral fold 'below; shell glossy, subtranslucent. 

 Species 5-7. 



ZONIFERELLA. - - Shell glossy, greenish-black with a white 

 peripheral band; aperture Bulimoid. Species 8, 9. 



1. S. HANLEYI (Pfeiffer). PI. 37, figs. 87, 88. 



Shell subimperforate, oblong-subfusiform, thin, pellucid, 

 uniform brown. Spire long, rather acute; whorls 7, rather 

 flattened, crenulate-striate at the impressed suture, the last 

 whorl obliquely descending, about two-fifths the total length. 

 Columella nearly straight. Aperture oblong-oval, light blue 



