HELIX §. U. 
123 
dus; apertura perobliqua, depresse securilbmiis ; perist. simplex, 
rectum, margine columellari subincrassalo. — Diam. maj. 16, 
miu. 14, ait. 5 mill. (Mus. Cuming.) 
Helix Sioainsoni Pft\ in Proc. Zooi. Soc. 1846. p. 28. 
Habitat in insula Tahili (Tucker). 
31S\ H. TroUus Gould. f 
T. variabilis , depresso-conica, subdiscoidea, leviter et obtuse 
striata, flavescens, subtus convexa, in umbilicum amplum incur- 
vata, carinata: carina utrinque linea spirali castanea marginata 
(interdum coloribus inversis); anfr. 5 /a rotundati; apertura se- 
milunaris, superne angulata; labrum acutum. — Lat. ait. 
yio poli. (G. ) 
Helix (Caracolla) Troilus Gould 1 8 46. Exped. shells p. 23. 
Habitat in insulis Samoa. 
Obs. «Haud dissimilis H. explanatae Quoy, sed minor, magis iimbili- 
caia, elc. » 
318'*. H, Gressida Gould. ^ 
T. variabilis , solida, depressa, lenticularis, acute carinata, 
nitida, dense et acute striata, coloribus flars^o -viridibus et casta- 
neis coalescentibus fasciata, infra subpianulata, umbilico magno 
et profundo perforata; anfr. 5 vix convexi; apertura triangularis; 
labrum acutum; faux lilacina. — Lat. Vio, ait. ^i^jolL (G.) 
Helix O^essula Gmdd 1 846. Exped. shells p. 23. 
Habitat in ins. Samoa et Taheiti. 
Obs. «Forma fere sicut H. acies , sed subtus planior et minor.» 
y' 319. H. acutimargo Pft*. 
T. umbilicata, depressa, supra planiuscula, basi convexa, 
tenuis, pellucida, pallide cornea, acute carinata, supra carinam 
striis nonnullis confertis, concentricis notata; anfr. G lente accre- 
scentes; umbilicus mediocris, pervius; apertura angulato-lunaris; 
perist. simplex, acutum. — Diam. maJ. 16, min. li/a, ait. 6 mill. 
(Coli. Nr. 167.) 
Helix aculimarcfo Pfr, in Proc. Zool. Soc. 1845. p. 40. 
— — Chemn. ed. II. Helix N. 620. t. 97. f. 1 —3. 
Habitat in insula Negros Philippinarum (Cuming). 
Obs. Similis speciminibus junioribus H. compressae, qualia circa Fiume 
legi, a quibus dilTcrl umbilico angusliorc, anfractibus angustioribus ct sculptura. 
y 320. H. radula Pfr. 
T. umbilicata, depressa, sublenticularis, solidiuscula, pallide 
cornea, carinata, striis incrementi confertis et lineis acute promi- 
