TERRESTRIAL MOLLUSCA INHABITING SOCIETY ISLANDS. 29 
Mr. Pease’s Pithys Atiensis, which I add to the Synonymy, is thus described :— 
“'T. orbicularis, tenuiscula, late umbilicata, confertim costulata, flavido et rufo 
tesscllato-strigata ; spira vix elevata, apice obtuso; anf. 9, convexi, ultimus ad peri- 
pheriam rotundatus; sutura bene impressa ; apertura obliqua, subcircularis, lamellis 
carens; perist. simplex, rectum. Diam. 3, alt. 12 mill.” (Pease). 
The Harvey Island shells, which attain a larger size than those found elsewhere, 
differ none in shape and sculpture, and the coloration is the same as Society Island 
specimens. ‘The umbilicus varies from one-fourth to one-third the greater diameter 
of the shell. 
T also add to the synonymy Mousson’s Patula vicaria, described as follows :— 
“'T. parvula, aperte umbilicata, orbiculato-depressa, regulariter et tenuiter costulato- 
striata, striis squamulosis, faciis pallide corncis et fuscis radiatim picta. Spira planiuscula, 
subarcte spirata; summo minuto, levigato, obtuso; sutura perimpressa. Anfr, 44, 
lente accrescentes, convexi; ultimus lente descendens, supra paulo tumidulus, deinde 
regulariter rotundatus. Apertura subverticalis (15° cum axi), exacte lunato- 
semicircularis, plicis destituta. Perist. rectum, acutum; marginibus convergentibus ; 
dextro et basali antrorsum leniter biarcuatis, columellari non reflexo, nec protracto. 
Umbilicus ¢ diametri equans. Alt. 1-5, diam. 3 mill. Rat. anfr. 7: 2. Rat. apert. 
1:1” (Mousson). 
With the exception of being a trifle smaller, is not dissimilar in any respect from 
the Harvey Island shells. 
The above author has described a variety of modicella from the Kermandec or 
Sunday Island, as follows :-— 
“Anfractibus magis rotundatis, costulis, sed tenuibus; albescens, maculis et flammulis 
rufis transverse picta ; diam. 3, alt. 1-2 mill.” (Mousson). 
P. consrminis, Pease. Plate II, figs. 12, 12a, 120. 
Helix consimilis, Pease, Amer. Jour. Conch., 1867, p. 227. Pfeiffer, Mon. Hel., vii, p. 262. 
Helix radiella, Carpenter (not of Pfeiffer), Proe. Zool. Soc., 1864, p. 675. 
Pitys consimilis, Pease, Proc. Zool. Soc., 1871, p. 474. 
Patula societatus, “ Mousson,” Schmeltz, Cat. Mus. Godeff., iv, p. 73. Paetel, Cat. Conch., 
p. 95. Pfeiffer, Mon. Hel., vii, p. 482. 7 
Patula consimilis, Schmeltz, Cat. Mus. Godeff., v, p. 207. 
Common and diffused throughout all the larger valleys of Raiatea, where it is 
peculiar. Mr. Pease’s habitat, “ Tahiti,” is wrong. I collected all his type examples 
at the former island. 
The spire is convex, the first and second whorls planulate and the suture channeled. 
The whorls are narrow, slowly and regularly increasing, turgid next to the suture and 
the rib-like striw are very thin and closely set. The aperture is nearly vertical and 
the parietal region with one or two lamin. 
5 JOUR. A. N.S, PHILA., VOL. IX. 
