147 
Ampluria rotundata. — Shell remarkably globose; length 
and breadth equal, dark brown, but becoming olivaceous towards 
the aperture : spire but little elevated : suture moderately impress- 
ed : body whirl a little undulated instead of being wrinkled ; these 
undulations being very perceptible to the finger within the shell ; 
aperture within on the margin thickened equally all round, and 
fulvous, with a slight groove for the reception of the operculum, 
hardly visible but palpable : within somewhat perlaceous ; a little 
darker on the columella : umbilicus small, narrow : operculum 
calcareous, deeply and concentrically rugose, so as to appear strati- 
fied ; nucleus on the side towards the labium sub-marginal. 
Length, less, than one inch and four-fifths; greatest breadth, 
about the same. 
For this interesting species, we are indebted to Capt. Leconte, 
of the Topographical Engineers, who informed me that he found it 
in St. John’s river, in Florida. 
It is most closely allied to the A. glohosa, Swainson, a native of 
the rivers of India. But that shell is rather less globose, and does 
not appear to have the almost regular, but slightly elevated and 
very numerous undulations so perceptible towards the aperture on 
the body whirl of this species ; which has also a few hardly per- 
ceptible, distant, brownish bands, particularly towards the base. 
It may, however, be only a variety of that species. 
Ampullaria depressa. — A s the name depressa, of the Ap- 
pendix to Long’s Expd. p. 264, is preoccupied by Lamarck for a 
fossil species, it may be changed to paludosa. 
Ampullaria elagellata. — Shell subglobose, olivaceous 
brown, with 15 or 16 revolving, dull reddishbrown, slender bands 
spire conic, moderately elevated, acute : body whirl regularly 
rounded, more obviously undulated or obtusely wrinkled near the 
aperture : ’umbilicus free, obvious : lab rum a little dilated : within 
reddish brown : labium, columella, and the margin of the labrum 
white : operculum horny. 
Length, over one inch and a half ; greatest width, one inch and 
two-fifths. Inhabits Mexico. 
Occurs in plenty a short distance below Vera Cruz. We found 
them immediately behind the sand-hillocks of the coast, in situa- 
tions which, in rainy seasons, are covered with fresh water. We 
did not see a living specimen ; they were mostly decorticated and 
