GASTEROPODA. 69 
rior portion. The base is rounded, tending rapidly to a deep umbili- 
cal depression, with a small perforation. Aperture small, crescentic, 
having a small, acute tooth on the right margin, a transversely oblong 
one at base, and a prominent, compressed, curved, nearly horizontal 
one on the columella, thus giving a three-lobed outline to the aperture. 
Peristome white, slightly reflected, having a very profound constriction 
of the whorl directly behind it. 
Diameter one-fourth of an inch; axis three-twentieths of an inch. 
Found near the Sacramento River, California. Pzckering. 
Its general form and its aperture are very much like H. zn/flecta, 
Say, though it isa much smaller shell, and the teeth of its aperture 
are much less developed. Its peculiar surface, resembling, when 
closely examined, a scaly coat of mail, is highly characteristic. 
Figures 39, 39 a, two views of the shell, enlarged; 39 J, natural 
size ; 39 c, sculpture, magnified. 
Hetix Devia (Gould). 
Testa orbiculato-depressa, oblique striata, dilute viridi-cornea, umbilico 
modico canaliculato perforata: spira anfractibus sex convexis, ultimo 
ad peripheriam rotundato: apertura transversa, oblique lunata, ad 
anfractum penultimum unidentata, dente trigono ; labro albo, late 
reflexo, ad basim horizontah, umlilicum alhquanto ambiente. 
Heliz devia, Gouin; Proceed. Boston Soc. Nat. Hist., 11.165. Aug. 
1846. Expedition Shells, 17. 
Suet. solid, depressed globose, of a pale yellowish horn-colour, 
rather finely marked with the lines of growth. Whorls six, convex, 
separated by a well-defined suture, and forming a rounded spire. Be- 
neath, slightly convex, and perforated by a moderate sized umbilicus, 
which appears to have an obtuse channel revolving on the whorls 
within it. Periphery rounded. Aperture transverse, obliquely lunate ; 
lip white, rather broadly reflexed, horizontal at base, and abruptly 
turning up to form a short columella, where it dilates, and partly sur- 
18 
