V 
HELIX (THALASSIA) GUTTULA, Pfeiffer. 
Helix guttula, Pfr., Zeit. f. Malak., 1853, p. 53; vol. 3, p. 626 ; 
vol. 5, p. 55, No. 74. Nanina guttula, Gray. 
Shell imperforate, convexly-depressed, thin, very smooth, shining, 
pellucid, fuscous-horny; spire vaulted over; suture inconsiderable, 
sub-marginated ; whorls 5, rather convex, slowly increasing, the last 
rounded at the periphery, impressed in the middle beneath, callous ; 
aperture slightly oblique, lunar; peristome simple, straight, acute, basal 
margin slightly arcuate, thickish at the columella. 
Diam., greatest, 5 ; least, If; height, 2f mill. 
Hab., New Zealand. Nicobar Islands (Zelebor). 
HELIX (THALASSIA) TULLIA, Gray. 
Nanina Tullia, Gray, P.Z.S., 1849, p. 165. Helix Tullia, Pfr., 
M.H.V., vol. 3, p. 35; vol. 5, p. 55, No. 75. 
Shell imperforate, depressed, thin, closely- ribbed, diaphanous, tessel¬ 
lated with pale-yellow and rufous ; spire slightly convex ; whorls 5, 
rather convex, narrow, the last not descending, obscurely angled at the 
periphery, impressed in the middle at the base; aperture sub-vertical, 
lunar ; peristome simple, straight, basal margin slightly arcuated. 
Diam., greatest, 4 J ; least, 4 ; height, 2 mill. 
Hab., New Zealand (Greenwood). 
HELIX (THALASSIA) MAKL®, Gray. 
Helix Maries (Nanina), Gray, Dieff. Trav., vol. 1, p. 262. Helix Marioe., 
Pfr., M.II.V,, vol. 3, p. 39; vol. 5, p. 58, No. 95. Helix umbra- 
culitm, Pfr., P.Z.S., 1851. 
Shell imperforate, somewhat lentiformed, rather thin, finely plaited, 
unctuously glossy, greenish-horny, obscurely painted with narrow rufous 
streaks descending forwardly; spire convexly-conoidal; apex acute ; 
suture margined; whorls 5J, flattish, acutely keeled, the last not 
descending, somew'hat convex at the base, obscurely tessellated with 
rufous; aperture oblique, depressed, sub-triangular; peristome simple, 
acute, straight, slightly arcuated at the basal margin, shortly reflected at 
the columellar margin. 
Diam., greatest, 7|-; least, 7 ; height, 3§ mill. 
Hab., New Zealand (Strange). 
HELIX (THALASSIA) GRANUM, Pfeiffer. 
Helix granum, Pfr., P.Z.S., 1857, p. 107 ; M.H.V., vol. 4, p. 20 ; 
vol. 5, p. 63, No. 143. 
Shell perforated, turbinately-globose, thin, very closely and finely 
striately-ribbed, pale horny, irregularly variegated with reddish 
markings; spire conoidal, slightly acute ; whorls 5£, convex, the last 
