234 COLUMELLA. 



C. edentula has been reported from the English Upper Plio- 

 cene, and Pleistocene of Europe and the United States, but 

 the genus has not been positively identified from earlier for- 

 mations. Isthmia dubia Newton and Harris, Proc. Malac. 

 Soc. London, I, 1894, p. 72, pi. 6, f. 5, from the Oligocene of 

 Headon Hill, was considered congeneric with C. edentula by 

 its authors, perhaps correctly, but the figure of the shell is 

 more that of Vertigo. 



The species are grouped geographically, thus : 



1. Species of the Atlantic Islands, Nos. 1, 2. 



2. European and Asiatic species, Nos. 3-6. 



3. American species, Nos. 7-11. 



4. Hawaiian species, Nos. 12-14. 



1. Species of the Atlantic Islands. 

 1. Columella microspoba (Lowe). PI. 30, figs. 2, 3, 4. 



Shell minute, distinctly perforate, ovate-conic, somewhat 

 trochiform or turbinate, short, very obtusely obsoletely sub- 

 striate, brownish-corneous. Whorls 5, convexly swollen, the 

 last obtusely angular with abruptly truncate or somewhat 

 flattened base; suture impressed. Aperture depressed, trans- 

 versely semioval, wider than long, occupying one-third of the 

 total length, wholly toothless; columella with a reflected 

 lamina ; peristome equally arcuate-rounded throughout, simple, 

 acute. Length I14 to iy 2 , diam. 1 to I14 mm.; apert. % to 

 y 2 mm. long; 5 whorls (Lowe). 



Length 1.9, diam. 1.35 to 1.45 mm.; 5y 2 whorls (Madeira). 



Madeira: at high elevations on ferns and grass stems in 

 moist, cloudy spots in wooded regions ; Lombarda das Vacas, 

 at the Fanal, the Montado dos Peceguiros, S. Antonio da 

 Serra and many other places (Wollaston). 



Azores: S. Miguel, Fayal and Pico, in the Caldeiras and 

 among fallen leaves of Persea azoriea (Morelet and Drouet). 



Canaries: Teneriffe at Las Mercedes, Ycod el Alto etc. 

 Palma, on the ascent to the Cumbre above Buenavista; ob- 

 tained from the fronds of ferns by sweeping (Wollaston). 



Pupa microspora Lowe, Ann. Mag. N. H., IX, 1852, p. 275 ; 



