86 PARTULINA, LANAI. 



peristome unexpanded, labiate within, the right margin some- 

 what straightened, columellar margin dilated, vaultingly re- 

 flexed. Length 18^, diam. 9, aperture 8x83^ mm. Sand- 

 wich Is. (P/'r.). 



Dr. Newcomb and all more recent -authors have agreed in 

 considering A. fulva a synonym of variabilis. Specimens 

 measure: Length 17 to 18, diam. 10, aperture 8.3 mm. The 

 lip-callus is white, or brown with a white lip-edge. The widest 

 specimens approach semicarinata, but none are so wide as that. 

 It is sometimes cream-white. 



Mr. Thaanum found P. variabilis lower, P. semicarinata)' 

 higher on the main ridge of Lanai. 



44a. Var. lactea Gulick). PL 22, figs. 15, 16. 



11 Shell sinistral, perforate, acuminately ovate, solid, shin^- 

 ing, finely striated, and microscopically very finely decus- 

 sated, color ivory white ; apex acute ; spire conical, with out- 

 lines slightly convex; suture marginate, slightly impressed; 

 whorls 6^, flatly convex; columellar fold central, brown, 

 strong; aperture oblique, sinuately oval, reddish brown 

 within ; peristome white, thickened within ; with external mar- 

 gin arcuate, slightly reflected anteriorly; columellar margin 

 dilated, slightly detached; parietal margin thin. Length 22, 

 breadth 11%; length of body-Whorl 15 mm. Weight 8 

 grains " (Gulick). 



Lanai: S. T. Alexander, D. Thaanum. 



The shell is rather snow-white than ivory-white, the colu- 

 mella brown, tip of the fold paler, lip-callus purple-brown, 

 interior lilac. The spire is straightly conic, whorls but very 

 slightly convex. It is minutely but constantly perforate. It 

 is a very beautiful shell, differing from the white form oc- 

 curring in some variabilis colonies by its darker aperture. In 

 a series of about fifty before me, all are sinistral. 



Length 18 to 19, diam. 10 mm. 



Length 16.8, diam. 9 mm. 



45. P. SEMICARINATA (Newcomb). PL 21, figs. 1 to 4, 13, 15. 



" Shell dextrorsal, solid, ovately-conical, longitudinally 



sttbstriated ; whorls 5, flattened, marginate above the last, an- 



