BY THE REV. J. E. TENISOK-WOODS. 
1055 
19. Clausilia, Draparnaud, Hist. Nat. d. Moll, terrest. et fluv. 
pp. 24, 29, 68. 
Shell iusiiorm, usually sinistral ; aperture elliptical or pyriform 
with a posterior sinus conti’acted by lamellae closed when adult by 
a moveable shelly plate (Clausilium); peristome continuous, reflected. 
Animal with a short obtuse foot ; upper tentacles short, lower 
small ; lung and reproductive orifices on the left side ; jaw finely 
grooved. 
Radula like Helix, but both rows very numerous, sometimes as 
many as 120 x 50. About 700 species, of world- wide distribution. 
The peculiarity of the genus is the Clausilium, which is developed 
ill the adult state. The animal secretes an elastic calcareous 
filament attached to the columella, round which it makes a half 
turn. At the free end is a spoon-shaped, lamina, smaller than the 
aperture, but fitting it. Its elasticity enables the animal to push 
it on one side when walking, and to use it as a door when within 
the shell, securing it against intrusion. 
Clausilia moluccensis, von Mart. Monatsber. Berk Ak, 
Apr. 1864, p. 270 ; (Phaedicsa), Ostas. Zool. II. p. 381, pi. 22, 
fig. 19; Pfr. Mon. Hel. VI. p. 412. 
Halmahera ; Ternate. 
Cl. penangensis (Piiaedusa), Stol. Jour. As. Soc. Beng, 
XLII. 1873, p. 27, pi. 3, figs. 4-6; Pfr. Mon. Hel. VIII. p. 465. 
Penang Hill. 
Cl. sumatraxa, von Mart. Monatsber. Berl. Ak. April, 1864, 
p. 270 ; ( Phaedusa), Ostas. Zool. IT. p. 379, pi. 22, fig. 17 ; Pfr. 
Mon. Hel. VI. p. 410. 
.Sumatra. 
Cl. iiELDii, Kii.st. p. 27, pi. 2, figs. 29-31 =C/. javana, Pfr. 
Mon. Hel. II. p. 405. 
Java. 
67 
