H 
382 Binney's Monograph of the Helices 
t 
.24. HELIX TRIDEIMATA, 
Plates XVII and XVIII. 
H. testi depressi, profundé umbilicata, corneo- -rufescente ; anfrac- 
tibus — striis distinctis, crebris, obliquis ; apertura conti 
trilobatà labro albo, reflexo, dentibus duobus instructo ; columella 
dente albo sub-arcuato arma ata. 
E 
x. Synonyms AND REFERENCES. 
i 
Helix tridentàta, Bay. Nich. Encyc., Am. Ed., IV. 
3 Pi. ii , fiz. 1, very bad figure. ` 
Férussac. Hist. des Moll. Pl. vx, fig. 3. 
Wood. Index Test. Sup. Pi. vu., fig. [^ 
Deshayes. Encyc. Méth., Vers; IL 213. 
Lamarck. , Anim. sans Vert, 2d edit., "n 
5. 
Helix era Say. Journ. A. N. S. Philad., I. 119. 
DESCRIPTIÓN. Ti 89 E 
Animal. Dark. bluish slate-color, deeper on the 
head, back, and tentacule ; length of superior ten- 
tacule about.a quarter of an inch; foot narrow, 
equal i in length to nearly twice the rni of the 
ell, terminating in an acute angle. 
^ Shell. Depressed, a little convex ; BA 
russet-brown ; whorls four and a half to six, : crossed 
obliquely by numerous acute, raised lines; aperture 
trilobate, more or less contracted by a groove behind 
-the lip ; lip white, reflected, its outer contour rounded, 
_ furnished on its inner margin with two acute project 
ing teeth ; pillar-lip with a white, projecting, slightly 
