GASTEROPODA. 
Synonym, Tebennophorus, Binney. 
Animal elongated, convex, tapermg behind, entirely covered 
by athin mantle; respiratory orifice near the head; jaw smooth. 
No shell. 
Distribution, 9 species. North America. 
Sub-genus :—Meghimatium, Hasselt. Syn., Incilaria, Benson. 
Body depressed, rounded at the end. 
Distribution, 4 species. Jaya, Chusan. 
Famity LY.—LIMN4#IDz.* 
PoMPHOLYX, Lea, 1856. 
Etymology, pompholua, lat. bulla. 
Type, P. effusa, Lea. Sacramento river, California. 
Shell gibbosely rounded, drawn back beneath, flattened 
above, imperforate; spire depressed; aperture very large, 
nearly round, effuse; outer lip acute, inner lip thickened, 
flattened. 
Animal with two long tentacles, bearing eyes, and a second 
pair of eyes at the base on the inner side of the tentacles. 
Distribution, 2 species. Western America. 
PITHARELLA, Edwards, 1860. 
Type, P. Rickmani, Ed. ‘‘ Woolwich and Reading Series,” 
Peckham and Dulwich, London. 
Shell partaking of the characters of Limnea and Chilinia, 
subcylindrical; aperture oval, rounded in front, narrowed 
behind; columella straight, or very obliquely twisted, arched 
anteriorly ; outer lip simple, acute; inner lip thickened. 
The species 1s associated with estuarine shells, remains of 
mammals and terrestrial plants. 
VALENCIENNESIA, Rosseau, 1842. 
Dedicated to the late Professor Valenciennes of Paris. 
Type, VY. annulatus, Ros. ; associated with fresh-water shells 
in a tertiary deposit, near Kertch, Crimea. 
Shell resembles a gigantic Ancylus; apex much incurved; 
surface concentrically marked. A _ longitudinal plication 
extends from the apex to the right border, and corresponds 
with an internal channel; there is a second but less distinct 
plication on the left side. 
CAMPTONYX, Benson, 1858. 
J'ype, C. Theobaldi, Bens. Guzerat. 
* See p. 300. 
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