THE NAUTILUS. IA: 
POTAMOLITHUS JACUHYENSIS, N. SP. 
BY H. A. PILSBRY. 
Shell turbinate globose, the last whorl with a “ shoulder,” pro- 
duced by an obtuse but distinct angulation of the whorl above its 
middle ; solid and strong, smooth, except for light growth lines, cov- 
ered with a strong, dark brown cuticle, becoming reddish on the spire 
and green behind the outer lip. Spire low conic, whorls about 43, 
those of the spire but slightly convex, the last large, obtusely angular 
above, rather flattened peripherally, the base somewhat concavely 
tapering. Aperture large, rather dilated, oblique, livid within, be- 
coming blue-white toward the lip and on the inner margin ; peristome 
continuous, blunt, thickened within at the upper angle, the outer lip 
a little waved or sinuous, inner margin heavily calloused, rounded, a 
narrow columellar crescent defined by an arcuate angle. Alt. 6.5, diam. 
5.3, greatest length of aperture 5 mm. 
Rio Jacuhy, Rio Grande do Sul, Brazil (Dr. H. von Ihering) 
This species differs from P. lapidum in the angular last whorl, 
more heavily calloused, parieto-columellar margin, much larger aperture, 
and the angle defining a narrow, crescentic columellar area. P. orbig- 
nyt Pils. is more closely allied than any other known species, but in 
that the body whorl is more distinetly biangular, the outer lip is more 
expanded and distinetly varixed, ete. 
The species of this genus already described by d’Orbigny and my- 
self, came from La Plata, Parana and Uruguay rivers. The present 
form is interesting as being from the Jacuhy, a stream flowing into 
the Atlantic instead of into La Plata. 
For previous references to this genus, under the names Paludes- 
trina, Lithoglyphus and Potamolithus, see d’Orbigny, Amér. mérid., 
p- 382; E. von Martens, Malak. Blatter, 1868, p. 192; H. von 
Ihering, Malak. Blatter (n. F ) VII, p. 96, and Pilsbry, Nautilus X, 
pp- 86, 119. 
——.614 a — 
REMARKS ON THE AMERICAN SPECIES OF CONULUS. 
BY HENRY A. PILSBRY. 
In most parts of the world there occur small land snails with thin, 
yellow or brown glossy shells, conical, pyramidal or teocalli shaped, 
with the axis imperforate or barely perforated. The foot has pedal 
grooves and the side-teeth are thorn-shaped, with two or more points, 
