212 SYSTEMATIC PALEONTOLOGY 



but imperforate ; canal moderate and slightly curved ; surface marked by 

 about ten rounded, prominent, longitudinal ribs, crossed by 18 or 

 20 revolving lines between some of which exist traces of finer lines, 

 the latter visible only on well preserved specimens. There are also visil)le 

 the usual lines of growth." Gabb, 1860. 



Length, 24 mm. ; diameter, 14 mm. 



Occurrence. — St. Mary's Formation. St. Mary's Kiver. Choptank 

 Formation. Greensboro. 



Collections. — Maryland Geological Survey, Johns Hopkins University, 

 Philadelphia Academy of Natural Sciences, Wagner Free Institute of 



Science, Cornell University. 



>• 



Suborder STREPTODOMTA. 



Superfamily PTENOGLOSSA. 



Family SCALID/E. 



Genus SCALA Humphrey. 

 SCALA SAYANA Dall. 



Plate LIU, Figs. 1, 2. 



Scalaria clathrus Conrad, 1830, Jour. Acad. Nat Sci. Phila., vol. vi, 1st ser., p. 211. 



Scalaria clathrn.i Conrad, 1842, Proc. Nat. Inst., Bull, ii, p. 187. 



Scala snyava Dall, 1889, Bull. Mus. Comp. Zool., Har., vol. xviil, p. 308. 



Scala saycma Dall, 1889, Bull, xxxvii, U. S. Nat. Mus., p. 132, pi. 1, fig. 10. 



Scala Sayana Dall, 1890, Trans. Wagner Free Inst. Sci., vol. iii, pt. i, p. 158. 



Description. — "A white shell with nine well-marked varices continuous 

 to the apex, which has a smooth, translucent, pale brown nucleus of about 

 three whorls. . . . The interstices are polished, smooth, with occasional 

 faint microscopic spiral strise." Dall, 1889. 



Shell elongate, ten-whorled ; varices 7 to 11, usually 9, somewhat cari- 

 nated ; mouth elliptical. Xo spiral sculpture is visible on any of the Mio- 

 cene specimens. 



Length, 16 mm. ; diameter, 5.5 mm. 



Occurrence. — St. Mary's Formation. St. Mary's Eiver, Cove Point, 

 Langley's Blujff. Choptank Formation. Jones Wharf, Governor Eun 

 (lower bed). Turner, Greensboro. 



Collections. — j\Iaryland Geological Survey, Johns Hopkins University, 

 Wagner Free Institute of Science, Cjornell University. 



