1871.] MR. HARPER PEASE ON POLYNESIAN LAND-SHELLS. 461 



been discovered since that the species abound on all the islands of 

 the several groups, even on the low sandy Atolls. 



So far as known, they may be arranged in three groups, viz. : — 

 first, V. nitens, Pse., &c, white, pellucid, nearly smooth ; second, V. 

 lyrata, Gld., striatula, Pse., &c, generally oblong in shape, distinctly 

 ribbed, aperture campanulate, modified by the transverse grooves on 

 last whorl ; and third, V. costulosa, Pse., more abbreviate in shape, 

 sometimes nearly globular, finely ribbed or elevately striate, and 

 aperture nearly circular. 



The following are new species. 



Vertigo striatula, Pse. 



T. cylindracea, oblonga, solidiuscula, sinistrorsa, umbilicata, longi- 

 tudinaliter oblique et jlexuose forte costata, interstitiis transversim 

 tenuiter striatis ; anfr. 5, rotundato-convexi, plerumque medio 

 rotundatim angulati, ultimus vix porrectus, medio concentrice late 

 sulcatus, circa umbilicum rotundato-angulatus, basi compressus ; 

 apex obtusus ; sutura bene impressa ; apertura subquadr angular is, 

 basi rotundata, lamellis 3 coarctata, inpariete aperturali 2,primo 

 magno, cum labro continuo, secundo mediano, interno, in margine 

 columellari superne 1, ad labium juncta ; peristoma continuum, 

 crassiusculum, vix expansum et reflexum, labro postice sinuoso ; 

 rufo-castanea, costis albidis. 



Alt. 2k, diam. 1|. 



Hab. Insula Hawaii. 



Vertigo armata, Pse. 



T. ovata, vix oblonga, nitidiuscula, dextrorsa, perforata, longitudi- 

 naliter tenuissime striata, interdum remote, tenuiter filo-costata, 

 sub lente subtilissime granulosa, fulvescenti-cornea, fills albidis ; 

 anfr. 4|-5, rotundato-convexi ; apex obtusus; apertura subqua- 

 drangularis, fere circularis, dentibus 8 munita, in pariete aper- 

 turali 3, primo maxima cum labro continuo, secundo mediano, 

 intrante, tertio minimo, interno, in margine columellari 1, in mar- 

 ginibus basali et labiali 4, pro/unde sitis ; peristoma incrassatum, 

 rufescens, subexpansum, reflexum, marginibus disjunctis, labro 

 postice vix sinuoso. 



Alt. 2, diam. 1 1 mill. 



Hab. Insula Bolabola. 



Vertigo simplaria, Pse. 



T. tenuis, obeso-ovata, dextrorsa, rimata,flavescens, longitudinaliter 

 tenuiter striata ; anfr. 3, rotundato-convexi, ultimus planulatus ; 

 sutura valde impressa ; apex obtusus ; apertura fere circularis, 

 edentata; peristoma tenue, marginibus disjunctis; columella su- 

 perne patula, vix expansa. 



Alt. If, diam. 1 mill. 



Hab. Insulse Marquesas. 



Vertigo costata, Pse. 



T. cylindracea, oblonga, solidiuscula, dextrorsa, rimato-perforata , 



