170 PROCEEDINGS OF THE ACADEMY OF [1899. 



Suture well marked. Whorls but slightly convex. 12 below the 

 small nucleus, Avith projecting whorls, transverse to the axis. 

 Transverse ribs about 20, rather stout, nearly perpendicular, 

 rounded, separated by about equally wide, deep, concave spaces^ 

 terminating at the periphery of the body-whorl in clean-cut ends. 

 Base rounded, smooth. Aperture squarish, somewhat expanded 

 below, with rounded angles; inner-lip thickened, reflected. Entire 

 surface covered by very fine, microscopic strife. 



Length of the largest specimen (apex gone), 9 mm.; diameter, 

 2 mm.; length of aperture, li mm. 



Three live specimens (No, 79.013) were found at Sarasota Bay,. 

 Fla., by Mr. H. Hemphill. 



Three poor, worn specimens (No. 10,302, Peabody INIuseum) 

 from West Florida, collected by Col. Je\vett. 

 Turbonilla atypha, new species. 



Two badly worn, imperfect specimens (No. 70,537) from Mal- 

 donado Bay, in 3-6 fathoms. Uruguay, both destitute of apices 

 and having the outer-lip broken away, are so distinct from any 

 other species as to be worthy of mention. 



Shell of good size, long and moderately slender, thick, opaque 

 white, tinted with yellow at the sutures, with considerable lustre. 

 The larger specimen has 10 flattened whorls, having a slight bulge 

 just above the well marked suture. Transverse ribs about 20, 

 ill-defined, not reaching quite to the lower suture, broadly rounded, 

 straight, very oblique, gradually decreasing in prominence as the 

 shell increases, so that on the body-whorl they show but faintly. 

 Interspaces narrow and shallow. Base elongate, well-rounded, 

 smooth. Aperture badly broken; inner-lip considerably thickened 

 and reflected. 



Length of the larger specimen, 7^ mm. ; diameter, 14 mm. ; 

 length of aperture, about li mm. 



This species is more slender and more gradually tapered, with 

 fewer and less distinct ribs than T. Uruguayensis, described and 

 figured by Mr. Pilsbry, 1897. 



References to the original descriptions of the species of Turbonilla 

 belonging to this region. 



1826. Say, Thomas. — Journal Academy Natural Sciences of Phila. , 

 V, p. 208. Descriptions of Marine Shells Recently Discovered 

 on the Coast of the United States. 



