406 THE TERRESTRIAL MOLLUSCA INHABITING 



I include this species on the authority of Mr. Pease, who found it in a small 

 lot of land shells collected by Dr. Dean at Mangaia. 



GENUS SCALINELLA, Pease. 

 S. AFFiNis, Pease. 

 Bealia affinis, Pease, Amer. Jour. Conch., 1865, p. 288; 1866, p. 82, PI. 5, fig. 4. Pfeiffer, Mon. 



Pneum., Suppl. 3, p. 218. 

 Omphalotropis affinis, Pease, Jour, de Conch., 1869, p. 152. 

 Atropis affinis, Pease, Proc. Zool. Soc, 18tl, p. 4Y6. 

 ScoMnella affinis, Martens & Langk., Don. Bism., p. 59. Paetel, Cat. Conch., p. 124. Schmeltz, 



Cat. Mus. GodeflF., v. p. 102. ~ ~ 



Common on the ground in forests near the sea-shore at Aitutaki. 



Though referred by Mr. Pease to his genus or subgenus Atropis, it should," I 

 think, be embraced in Scalinella. In the above author's description he says, 

 '-'■ longitudinally indistinctly plicately-ribbed ; ribs close and somewhat oblique,'" and 

 " the above two species together with R. costata {Pease) and R. Tahitensis {Pease) 

 form a group in being ribbed longitudinally,''^ 



In the numerous examples now before me the ribs gradually fade away, so that 

 some specimens are perfectly smooth and undistinguishable from Atropis. It may 

 be considered an intermediate form connecting the two genera the same as certain 

 species of Atropis graduate into Omphalotropis. 



S. scALARiroRMis, Pease. 



Bealia scalariformis, Pease, Amer. Jour. Conch., 1865, p. 288; 1866, p. 82, PI. 5, fig. 3. Pfeiffer, 



Mon. Pneum., Suppl. 3, p. 217. 

 Scalinella scalariformis, Pease, Jour, de Conch., 1869, p. 159; Proc. Zool. Soc, 1811, p. 416. 



Martens & Langk., Don. Bism., p. 59. Schmeltz, Cat. Mus. Godeff., v., p. 102. 



Not uncommon on the ground in forests near the sea-shore at A tin. 



Dr. Pfeiffer, misled by the wrong localities in the " American Journal of Con- 

 chology" for 1866, page 82, has confused the habitat of this species with that of 

 Palaina scalariformis. Pease. The latter does not occur at the " Harvey Isles,'' as 

 quoted by that author, neither does the species under consideration inhabit 

 " Oulan" = Ponape. 



It differs from the preceding species in its larger constant ribs and more por- 

 rected body- whorl. The color is also darker. 



GENUS HELICINA, Lamarck. 

 H. PARVULA, Pease. 

 Helicina parvula, Pease, Amer. Jour. Conch., 1868, p. 156, PI. 12, fig. 10; Proc. Zool. Soc, ISll, 



p. 416. Paetel, Cat. Conch., p. 125. Schmeltz, Cat. Mus. Godeff., v., p. 99. Pfeiffer, Mon. 



Pneum., Suppl. 3, p. 249. 



