THE NAUTILUS. 15 



DESCRIPTIONS OF TWO NEW SPECIES OF POTAMOLITHUS. 



BY II. VON IHERING, SAO PAULO, BRAZIL. 



P. PATSANDUANUS II. Sp. 



Shell imperforate, solid, globose, olivaceous, nearly smooth. 

 Spire very short, conic, the apex eroded. Last whorl swollen be- 

 low the suture, rounded at the base and periphery. Aperture some- 

 what oblique, ovate. Peristome continuous, obtuse, black, the outer 

 and basal margins narrow, columellar and parietal margins wide, flat 

 and black. Length 4.8 ; diam., 3.9 mm. Paysandu, Uruguay. 



This species occurred in three forms : (1) that described above 

 as typical. 



(2) Form sinulabris, similar to the preceding, but with a sinus in 

 the upper part of the outer lip. 



(3) Form impressus, larger, with a concave zone at the upper 

 part in the last half whorl, and a sinus in the lip, which is thin and 

 sharp. 



P. FILIPPONEI n. sp. 



Shell imperforate, pyramidal, olivaceous with a reddish-brown band 

 at the penultimate whorl, smooth. Whorls 5, strongly convex, the 

 last strongly bicarinate, one carina peripheral, the other basal, 

 bounding a large concave umbilical area. Aperture very oblique. 

 Peristome continuous, outer lip thin, unexpanded, having small 

 rounded sinuses near the upper insertion, below the peripheral angle, 

 and at the base of the columella, which is narrow and straight. 

 Length 4.4, diam. 4 mm. 



Montevideo, Uruguay, type in Museu Paulista, collected by Dr. 

 Florentine Filippone. 



COMMON OK VERNACULAR NAMES FOR MUSSELS. 



BY DR. V. STERKI. 



While collecting along the Ohio River, I had some dealings with 

 the shell hunters, the men gathering clams for the button factories, 



