104 LIMN AIDA. 
PLESIOPHYSA, Fischer, 1888. Shell rather short. Central tooth 
of the radula 5-cuspidate, the median cusp the longest. P. striata, 
d’Orb. W. Indies. 
PECHAUDIA, Bourg., 1882. Shell like Physopsis, but dextral, 
oval, transparent ; columellar axis with a white lamella, strongly 
truncate at the base. P. Letourneuxi, Bourguignat. Algiers. 
CAMPTOCERAS, Benson, 1842. 
Distr.—3 sp. Swamps, in India. C. terebra, Benson (ce, 35). 
1 fossil species. Eocene; Sheerness-on-Sea, England. 
Shell sinistral, imperforate; whorls three or four, separate, 
flat, carinated above and below; suture widely and profoundly 
excavated; aperture large, elongate-elliptical; peristome thin, 
continuous. 
Animal has two obtuse, filiform tentacles, with large eyes 
placed between them; mantle not larger than the lips of the 
shell; foot short. 
The description of the animal corresponds nearly with the 
Limnophila, and the sinistral shell has caused authors to place 
it in Physade. 
CHILINA, Gray, 1831. 
Syn.—Dombeya, d’Orb, 1837. Potamophila, Swn., 1840. 
Distr.—18 sp. South America. Fossil, 1 sp. Miocene; 8. 
Am. C. puelcha, d’Orb. (ciii, 22). It replaces the Limnza of 
North America; lives in clear running streams. 
Shell dextral, oval, rather thin, usually ornamented with dark 
spots or wavy bands; columella thickened, with one or two 
strong, prominent folds, peristome simple. Tentacles large, 
flattened, with sessile eyes at their superior face ; pulmonary 
pouch with a well-developed protecting lobe; foot large, dilated 
in front, attenuated behind; genital orifices on the right side. 
No jaw? Central tooth small, 5-cuspidate, laterals and marginals 
multicuspidate, with a superior, external prolongation. 
PSEUDOCHILINA, Dall, 1870, Shell thin, covered with a rough 
fibrous epidermis ; spire elevated, acute. C. Limneformis, Dall. 
Chili. 
PITHARELLA, Edwards, 1860. 
Distr.—P. Rickmani, Ed. ‘“ Woolwich and Reading Series,” 
Peckham and Dulwich, London. 
Shell partaking of the characters of Limnzea and Chilina, sub- 
cylindrical; aperture oval, rounded in front, narrowed behind ; 
columella straight, or very obliquely twisted, arched anteriorly ; 
outer lip simple, acute ; inner lip thickened. 
The species is associated with estuarine shells, remains of 
mammals and terrestrial plants. 
