ierrestrial mollusca inhabiting society islands. 77 
P. EUSTICA, Pease. 
Partula rustica, Pease, Amer. Jour. Conch., 1866, p. 199 ; 1867, p. 81, PI. I, fig. 5 ; Proc. Zool. 
oc. , p 473. Schmeltz, Cat. Mus. Godeff., v, p. 207. Pfeiffer, Mon. Hel., viii,p. 205. 
artula aunculata, Carpenter (not of Broderip), Proc. Zool. Soc., 1864, p. 675. 
Partula crassilabris, Gloyne (not of Pease), Quar. Jour. Conch., i, p. 338. Hartman, Cat. 
I art., p. 9 ; Obs. Gen. Part., Bull. Mus. Com. Zool., ix, p. 187 (part). 
Partula pinguis, Garrett, MS. 
The metropolis of this species is in a large valley called Toloa, on the west coast 
of Raiatea, where it occurs in great abundance beneath decaying vegetation. It has 
migrated to the southward into two small adjacent valleys, but does not extend its 
range so far as Plapai, the next large valley, and the home of the allied P. crassilabris. 
It IS larger, less globose, the aperture more oblong, than the latter species, with 
which it has been confounded. Its chief character consists in the columellar region 
being, as it were, pressed in towards the aperture, nodulous on the inner margin, and 
subangulated at the base. The parietal tooth is less developed and more frequently 
absent than in crassilabris. The coloration is the same in the two species. Like the 
majority of the ground species, it varies in a greater or less degree in shape and size. 
Some forms almost exactly simulate P. Garrettii, not only in the outline of the shell, but 
in the peculiar shape of the aperture as modified by the columella being pressed inwardly. 
Occasionally examples occur which are so much abbreviated that they resemble P. 
crassilabris, but may readily be separated by the dissimilarity in the columeUar region. 
My P.jnnr/His, of which I have seen only a dozen examples, was found under decaying 
leaves in the mountain ravines, at the head of Vaioara valley. It certainly = rustica. 
P. LUGUBEis, Pease. Plate III, fig. 47. 
Partula lugubris, Pease, Proc. Zool. Soe., 1864, p. 672; 1871, p. 473. Pfeiffer, Mon. Hel., 
vi, p. 158. Schmeltz, Cat. Mus. Godeff., v, p. 207. 
Partula ovalis, Pease, Amer. Jour. Conch., 1866, p. 194; Proc. Zool. Soc., 1871, p. 473. 
Pfeiffer, Mon. Hel., viii, p. 205. 
Partula dentifera, Carpenter (not of Pfeiffer), Proc. Zool. Soc., 1864, p. 675 ovalis). 
Partula fusca, Hartman (not of Pease), Cat. Part., p. 6; Obs. Gen. Part., Bui. Mus. Com. 
Zool., ix, p. 182 (part). 
The six-cific centre of this ground species is in Vaiau valley, on the west coast of 
Raiatea, the northern limits of the range of P. formosa. It has not spread any to the 
southward, but, on the other hand, has migrated to the northward into Hapai vaUey, 
the headquarters of P. crassilabris, with which it is found associated. 
The Hapai shell was first described by Mr. Pease, under the name of lugubris, 
and, although nearly as abundant as the Vaiau form (= ovalis, Pse.), is smaller, 
thinner, more attenuated and more variable in color and fasciation. 
However, the difference between the two species is so slight that I think it best 
to unite the two forms. 
11 JOUR. A. N. S. PHILA., VOL. IX. 
