74 THE NAUTILUS. 



talus of red clay by the road side. These were the result of an hour's 

 search, and it is greatly to be regretted that no specimens were found 

 with the operculum. When taken they were considerably incrusted 

 with earthy matter. 



A TEXAS OIL WELL FOSSIL. 



BY T. H. ALDRICH. 



Some months since, Dr. Wm. B. Phillips, Director of the Texas 

 Mineral Survey, sent me a few fossils from Beaumont, Texas, ob- 

 tained at a depth of 390 feet in an oil well 

 on Spindle Top Hill. Among them was a 

 new species of Nassa, which has been de- 

 scribed in Bulletin No. 1 of the University 

 of Texas, Mineral Survey, July, 1901. De- 

 scription is herewith repeated, and a figure 

 added. 



NASSA BEAUMONTEN8IS Aldf. 



" Shell cancellated, whorls seven, the first two smooth, the others 

 with two strongly nodular transverse lines, except the body whorl, 

 which has six or seven. Aperture with both outer and inner lip 

 dentate, canal short. Length 8 mm., breadth 4 mm. This species 

 resembles Nassa bidentata Emmons, but is much more strongly nodu- 

 lar and has but two transverse or spiral ribs, and also possesses one 

 more whorl. The shell resembles a species of Phos, externally." 



DESCRIPTION OF A NEW UNIO FROM MISSOURI. 



BY WM. A. MARSH, ALEDO, MERCEK CO., ILLINOIS. 



Pleurobema missouriensis, new species. 



Shell smooth, obliquely triangular, rounded before, subbiangular 

 behind, moderately thick, very much thicker anteriorly, sides some- 

 what flattened, beaks wide, solid, incurved, ligament long, light 

 brown, epidermis light brown, without rays, growth lines numerous, 

 not raised, umbonal slope wide and rather flat, posterior slope wide, 



