46 
TERRESTRIAL 
MOLLUSCA INHABITING SOCIETY ISLANDS. 
()ccui)yiiig tliat part of the island nearest to the metropolis of the t> pe, and the other, 
which is fr(>qiiently deiitated, is distributed over the remainirig portion of the island. 
The beautiful P. hiUneata is confined to a single valley on the eastern coast, and P. 
planilahrum, which has its headquarters in the large Haamene valley, just to the 
southward of the home of the former species, has established a colony in the valley 
on the north side of the one occupied by P. bilineata. P. rnnhiUcatu, which shares 
the metrojiolis of phinilahriim, has, like that species, avoided intruding in the home 
of hilineota, but to the northward it occupies several valleys, slightly overlapping the 
northern range of P. virginea, which latter has its metropolis on the west coast, and, 
like P. tnnhilicida, ranges throughout several valleys north of its headquarters. 
Borabora, the smallest island inhabited by Parfidn, possesses a single species of a 
peculiar type, which has spread nearly all over the island without develo])ing a single 
local variety. 
Hybrids between P. elongata and P. tcenvda, and between P. (rarretfii and P. 
Thalia, are so common where those species come in contact, that I am inclined to 
believe they possess a certain degree of fertility. 1 have also detected several hybrids 
bc'twcen P. faba, var. si/baugalata, and P. virginea ; one between the arboreal P. 
imperforata and the terrestrial P. lagabris ; two between J\ Hne(da, var. strigosa, and 
l\ taaiiata ; about a dozen between the arboreal ]\ faba and the terrestrial P. raduda ; 
a number between P faba and P. fasca, and many between the latter and P. naidga- 
foria, as well as many between the latter and P. faba. I failed to det(>ct hybrids 
between the 'fahitian species, and found none at Iluaheine. 
Ihe examination of the animals of the various species has convinced me that they 
])ossess no reliable external leatures that will aid in their determination. The colora- 
tion ill all the species varies from pale cinereous, through all the intermediate shades, 
to black or dusky slate. The arboreal species arc generally lighter colored than the 
ground spiTies, and have a more expanded creeping-disk. The animals of I\ argaia, 
annectens, iargida and atteniada, have the ocular tentacles longer and more slender 
than the other species, and the exudation of mucus is much more copious and more 
viscid or tenacious than usual, reseiubliug in that respect the same difference as exists 
between tlie typical Helices and the arboreal Naniiue. 
P. Otaheitana, Bruguiere. 
Jiulimus OlaheitanuK, Bruguiere, Enev Meth ; t i » • 
ed u 281 Kiisior T>i y- ^eth., 1, p. 34u Lamarck, Anirn. sans Vert., Desli. 
ed.,p.281. Kuster,I>l.XIV,figs.5-6. Pfeiffer, Mon. Hel., ii, p 71 part 
JMi oTrT’ n f 108, PI. CXII, figs. 950, 951. ’ 
t ,r' “■ 1>- I»-'- Tow.. PI. XXXIV. 
Parlula Otaheitana, Perussae Prr,a cp r. ^ 
CoTOh. loon., P,. lit 13. Ts’l, T ’ »8- >«: 
ill, P. m. Couch n lof ’ fi ™ - 
-oodent; Obc. Oo„. P.,„., B.„, c„,„, Lcl.X! ^ 1 "”“’ 
