124 NEW-YORK FAUNA — MOLLUSCA. 
FAMILY TROCHID. 
ANIMAL with two contractile tentacles: eyes at their external bases, pedunculated. Marine 
and fluviatile. Sue.t very variable in form; aperture occasionally with its edges dis- 
united, but not forming a canal, and but rarely with a sinus in front. 
(EXTRA-LIMITAL.) 
Genus AmpuLtaria, Lamarck. Shell globular, ventricose, umbilicated: aperture oblong, entire ; 
margins united: no callosity on the pillar-lip. Lip acute, not reflected. An opercle. Aquatic, 
fluviatile. 
A. hopetonensis. (Lea, Tr. Am. Phil. Vol. 5, pl. 19, fig. 84.) Shell smooth, flattened above, umbi- 
licate, banded; sutures impressed; whorls five; aperture subovate. Color, yellowish or dusky 
brown ; aperture white. Length, 1+7; diameter, 1+4. Georgva. 
A. rotundata. (Savy, Des. terr. & fluy. shells, p. 22.) Shell very globose; spire little elevated; body- 
whorl undulated, instead of being wrinkled; aperture on the margin within, thickened equally all 
round, with a slight groove for the opercle; umbilicus small, narrow. Length, 1*8; width, 1°8. 
Florida. 
A. paludosa et depressa. (Say, Exped. St. Peter's, Vol. 2, p. 264, pl. 14, fig. 2. A. paludosa, Ip. 
MSS. penesma et disseminata.) Whorls four, slightly wrinkled; body-whorl more prominent 
above, somewhat flattened towards the suture; spire very much depressed; aperture oval, exhibit- 
ing the bands on the margin; umbilicus small, nearly closed. Color, pale olivaceous, obsoletely 
banded with obscure green, with numerous vertical and transverse greenish and brown lines; 
aperture somewhat glaucous. Length, 1+5; of aperture, 1°2. Florida. 
GENUS JANTHINA. Lamarck. 
Animal with a large head and extended snout, with the mouth at its extremity ; the latter with 
two vertical cartilaginous lips, armed with long recurved spines. ‘Tentacles two, conic, 
pointed, distant, and scarcely contractile. Eyes beneath the extremities of moderately 
long peduncles, which arise from the outer base of the tentacles. Foot oval, in two por- 
tions : the anterior concave and sucker-shaped ; the posterior flattened, thick and fleshy. 
Swimming appendages lateral, broad and fringed, consisting of a congeries of vesicles. 
Breathing cavity patulous, with two branchial pectinated series ; orifice of the ovaries in 
this cavity: male organ small, on the right side. Shell thin, brittle, globular or conoidal, 
ventricose ; spire low; aperture angular at the junction of the lips beneath ; pillar-lip 
twisted; lip witha sinus at the middle: all the species yet known, of a violet color. Opercle 
represented by a vesicular appendage attached to the posterior portion of the foot. 
