TERRESTRIAL MOLLUSCA INHABITING SOCIETY ISLANDS. 75 
P. virrava, Pease. Plate III, fig. 56. 
Partula vittata, Pease, Amer. Jour. Conch., 1866, p. 194; Proc. Zool. Soc., 1871, p. 478. 
Pfeiffer, Mon. Hel., viii, p. 200. Hartman, Cat. Part., p. 7; Obs. Gen. Part., Bul. Mus. 
Com. Zool., ix, p. 169 (excl. microstoma). 
Partula terrestris, Pease, MS. Coll. Pease, 1863. Paetel, Cat. Conch., p. 104. Gloyne, 
Quar. Jour. Conch., i, p. 388. 
Partula castanea, Pease, Coll. Pease, 1863. 
Partula faba, var., Carpenter, Proc. Zool. Soc., 1864, p. 675. 
Partula approximata, Pease, MS. Coll. Pease. Schmeltz, Cat. Mus. Godeff., v, p: 20%. 
Gloyne, Quar. Jour. Conch.,i, p. 338. Hartman, Cat. Part., p. 7; Obs. Gen. Part., Bul. 
Mus. Com. Zool., ix, pp. 179, 195. 
The shape of the typical vittata is oblong-conic, more or less compressly umbili- 
cated, and the spire, which equals half the length of the shell, bas subplanulate 
outlines. The ample, oblong aperture is considerably contracted by the intrusion of 
callus on the inner margin of the peristome, and the sides are nearly parallel. The 
peristome is rather thin, widely expanded and usually stained with brownish purple. 
The superior inner margin of the lip exhibits a shallow sinus. The columella is 
flattened, not nodose, and reflected over the umbilicus. The color is whitish, yellowish 
corneous, fulvous or horn-color, frequently with the basal third of the body and sutural 
band chestnut-color. Sometimes the apex is black or purple-black. ‘The parietal 
tooth, though small, is constant. My largest examples are 25 mill. long, and 11 in 
diameter. 
The type is restricted to the higher portions of Toloa valley, on the west coast of 
Raiatea, where it is not uncommon beneath decaying vegetation. It has not spread 
any to the northward, but, on the other hand, occurs in greater or less profusion, in a 
modified form (== approximata), in several small valleys on the southwest part of the 
island. No examples were discovered in Hapai or Vaiau, the headquarters of lugubris 
and ovalis, which two valleys are between Toloa and the small ones inhabited by 
approximata. 
The latter, which may be regarded as a variety of vittata, is characterized by its 
inferior size, smaller umbilicus, which is frequently impervious, smaller aperture, and 
less expanded lip. The parietal tooth is very seldom developed. ‘The fasciation is 
similar in the two forms, but occurs rarely in approximata. The latter differs, also, in 
being generally a lighter or darker chestnut-color, though both have similar horn- 
colored varieties. 
In the valleys on the southern part of the island, we find a gradual change from 
the typical P. approximata into the form known as P. terrestris, Pease, which latter 
connects the former with vitéata. It is of equal size, and exhibits a similar perfora- 
tion, large aperture and widely expanded lip. ‘The parietal tooth is seldom absent, 
and in coloration we find the same style of fasciation, but, like in approximata, it is 
less frequent than in viftata. It differs from approaimata in being generally light 
horn-color, with darker strigations. 
