26 TEKEESI'EIAL MOLLCSCA INIIABITIUa SOCIETY ISLANDS. 
Bays inhabits Tahiti and Samoa; the lattef location is undoubtedly 
S'lvs (Jour de Conch., 1870, p. 399) Creasida is a good species, and inhabits Raia . . 
nLilg personally collected all Mr. Pease’s Baiatea si, ells, and havmg now before me 
numerous .lupl.cates, I have failed to discover one which co.ne.des with Gouhl 
description. Mr. Pease’s Helix Imte, MS. (= Swainwm, var.), is the nearest allied 
form, but is much smaller, thinner and has a more convex base. 
Dr. Gould’s original description is as follows : 
“ T. variabilis, solida, depressa, lenticularis, acute carinata, nitida, dense et acute 
striata, coloribus flavo-viridibus et castaneis coalescentibiis fasciata, infra subplanulata, 
nmbilico magno et profundo perforata; anfr. 5 vix convexi; apertura triangularis; 
labnim acutum ; faux lilacina. — Lat. yVs ult. J poll.” (Gould). 
The only shell I can satisfactorily refer to the above diagnosis is a somewhat scarce 
species inhabiting two large valleys on the northwest side of Tahiti. ’Fhe localities 
are near the two principal harbors and probably were the first ones explored b} the 
naturalists of Wilkes’ Expedition. 
I have now before me five examples, the largest measuring 18 mill, in tlie major 
diameter and 6 in height. It is a solid, shining, depressed shell, with crowded, 
irregular, rather sharp, obliquely curved stria?, and 5-5^ subplanulate whorls. The 
suture is margined by the continuation of the acute periphery-keel. The flatly conve.x 
base exhibits a wide umbilicus in which may be easily enumerated all the volutions. 
The color is light yellowish brown, with or without a dorsal and basal light chestnut 
band wliich gradually fades into the ground color. Occasionally the basal band is 
obsolete, and the dorsal one so faint as not to be seen except in certain lights. The 
aperture is diagonal, depressed, securiform, with three angles rvhich suggested Gould’s 
“ apertura triangularis.” The peristome, above the carination, is trenchant, rectilinear 
and regularly curved from the keel to the columellar region, the inner margin 
strengthened with callus. 
T. SwAiNsoNi, Pfeiffer. 
Helix Swaimoni, Pfeiffer, Proc. Zool. Soc., 1846, p. 28; Mon. Hel., i, p. 122; {Videna) 
Vers., p. 132. Reeve, Conch. Icon., fig. 601. Carpenter, Proc. Zool. Soc., 1864, p. 675. 
Schmeltz, Cat. Miis. Gocleff., v, p. 95. 
Zonites Swaimoni {Rotula), H. and A. Adams, Gen. Moll., ii, p. 116. 
Helix scuta, Pease, MS. Coll. Pease, 1863. 
Helix lenta, Pease, MS. Coll. Pease, 1863. 
Nanina Swainsoni {Rotula), Paetel, Cat. Conch., p. 85. 
Trochomorpha Swainsoni, Pease, Proc. Zool. Soc., 1871, p. 474 (part). 
This BiKcics, whM, inhabits Ibaiatea and Tahaa, ocenrs in nearly all the laiare 
m It »» It is a ground species, and 
^^cather, mat be seen creeping a short distance up the trunks of trees. 
