TROCHATELLA §. 3. 4. 
333 
columella brevissime arcuata; perist. simplex, rectum, acutum. 
— Operc. membranaceum , fulvurn. — Diam. maj. 2 2 / 3 , min. 
2 r / 3 > alt. 2 mill. (Mus. Cuming.) 
Helicina tenuis Adams Contrib. to Conchol. N. 1. p. 14. *) 
Trochatella tenuis Adams Catal. 1849 et 1851. 
Habitat in insula Jamaica. 
10. T. rupestris 555 
T. pyramidata, tenuis, spiraliter striata, non nitens, citrina, 
rarius fuscidula; anfr. 5 plani, subdisjuncti, ultimi subcarinati, 
ultimus paululum descendens, basi convexiusculus ; apertura 
Integra, subtetragono-ovalis ; columella brevis, verticalis ; perist. 
simplex, acutum. — Operc. tenuissimum, pallide flavum. — 
Diam. maj. 4, min. 3 3 / 4 , alt. 3 mill. (Coll. Nr. 12.) 
Helicina rupcstris Pfr. in Wiegm. Arch. f. Nat. 1839. I. p. 355. 
— — Sow. Thes. N. 46. p. 10. t. 3. f. 120. 
Trochatella rupestris Pfr. in Zeitschr. f. Malak. 1848. p. 82. 
— _ — Chemn. ed. II. Troch. N. 7. p. 8. t. 5. f. 12 — 15. 
Habitat in insula Cuba ; in ripis fluvii Yumuri prope Matanzas ! 
§. 4. 
11. T. Tiiukervillii Gray. 556 
T. trochiformis , solidiuscula , oblique striata, liris granu- 
losis confertis cincta, albido-flavescens , seriebus 2 macularum 
rubrarum notata; spira conica, acuta; anfr. 6 T / 2 plani, ultimus 
basi convexiusculus , medio acute carinatus : carina valide 
dentata; apertura sub triangularis , intus alba, nitida; columella 
plana , breviter recedens , angulo recto cum margine basali 
juncta; perist. late expansum, undulatum, marginibus callo 
tenuissimo junctis. — Operc. tenue, testaceum, utrinque album. 
— Diam. maj. 20, min. 17, alt. 17 mill. (Coll. Nr. 13.) 
Helicina Tankervillii Gray in Zool. Journ. I p. 250. **) 
*) Shell small, thin, conic, pale brown, with distant slender raised spiral 
lines, decussated on the spire by inequidistant lines of growth ; whorls four 
and one-half, more inflated and subangular below the middle; aperture ellip- 
tical ; labrum sharp , not reflected ; labrum with a very thin deposit , colu- 
mella slightly pointed. — Mean divergence 90° ; length 0,08 ; greatest breadth 
0,09; least breadth 0,08 inch. — This is a Trochatella. (Adams 1. c.) 
**) T. subgloboso-conoidea, acute carinata, spiraliter squamulosa costo- 
striata, supra conica, infra convexa; peristomate reflexo albido, labio medio 
sinuato, columella subincrassata ; axis ? / 8 , diam. % poll. (Gray 1. c.) 
