TROCHATELLA 6$.3. 4. 333 
columella brevissime arcuata; perist. simplex, rectum, acutum. 
— Opere. membranaceum, fulvum. — Diam. maj. 2*/, min. 
2'/,, 21t. 2 mill. (Mus. Cuming.) 
Helicina tenuis 44dams Contrib. to Conchol. N. 1. p. 14. *j 
Trochatella tenuis -4dams Catal. 1849 et 1851. 
Habitat in insula. Jamaica. 
10. 'F. rupestris Efi. 555 
T. pyramidata, tenuis, spiraliter striata, non nitens, citrina, 
rarius fuscidula; anfr. 5 plani, subdisjuneti, ultimi subcarinati, 
ultimus paululum descendens, basi convexiusculus; apertura 
integra, subtetragono-ovalis; columella brevis, verticalis; perist. 
simplex, acutum. — Operc. tenuissimum, palhde flavum. — 
Diam. maj. 4, min. 3?/,, alt. 3 mill. (Coll. Nr. 12.) 
Helicina rupestris Pfr. in Wiegm. Arch. f. Nat. 1839. L p. 355. 
- -— Som. 'Thes. N. 46. p. 10. t. 3. f, 120. 
Trochatella rupestris Pfr. in. Zeitschr. f. Malak. 1848. p. 82. 
- n— Chemn. ed. IL. Troch.: N. 7. p. 8. t. 5. f. 12—15. 
Habitat in insula Cuba; in ripis fluvii Yumurí prope Matanzas! 
$. 4. 
11. ". amnmkervillii Gray: 556 
'T. trochiformis, solidiuscula, oblique striata, liris granu- 
losis confertis cincta, albido-flavescens, seriebus 2 macularum 
rubrarum notata; spira conica, acuta; anfr. 6'/, plani, ultimus 
basi convexiuseulus, medio aeute carinatus: carima valide 
dentata; apertura subtriangularis, intus alba, niüda; 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, conie, 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- 
tieal; 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 Il. c.) 
**) 'T. subgloboso-conoidea, acute carinata, spiraliter squamulosa costo- 
striata, supra conica, infra convexa; peristomate reflexo albido, labio medio 
sinuato, columeila subincrassata; axis ?/, diam. 9/, poll. (Gray l. c.) 
