108 BuivLKTIN 39 



of the growth linCvS: spirals consisting of low, raised threads with 

 wide interspaces; canal short, straight above but bent below, and 

 with three small, smooth folds on the columella above; aperture 

 with a thin outer lip. 



Length 46, diameter 17, last whorl 29, spire 24 mm. 

 A smaller and more delicate species than the preceding L. in- 

 fundibulum Gmelin. In the present shell, the ribs are sharp- 

 er and more pointed, and the canal is shorter and more strongl}'' 

 reflected backwards. The strongly frilled sutural band is lacking 

 or only imperfectly developed on infundibuluin. 



Gatun Stage: Port Limon. 



Latirus taiirus, n. sp. Plate 8, figure 4 



Shell large, slender, solid with the spire more than J^ the 

 height of the shell; whorls convex, with indistinct sutures; sculp- 

 ture of very regular, narrow ribs with deep interspaces, and cross- 

 ed by strong, ridge-like spiral cords; whorls about 9; axial sculp- 

 ture on last whorl with about 11 ribs; the ribs commence well 

 down on the base and continue to the upper suture and are 

 nearly in line across the spire- whorls to the apex; the spirals 

 consist of ridge-like cords and finer spiral threads; there are 

 2 principal spirals on the spire-whorls which cross the middle 

 of the whorls; there are 4 principal spirals on the last whorl 

 above the edge of the base, below which there are a few small- 

 er threads; the anterior canal has 2 strong cords and finer 

 threads are scattered over the whole shell; the anterior canal 

 is straight and stocky and carries at its base a deep but narrow 

 umbilical pit; the columella has 4 small folds; aperture subo- 

 vate, anteriorly extended to form the long narrow canal; out- 

 er lip smooth within. 



Height 60, diameter 25, aperture 32 mm. 



A large, solid and strongly sculptured shell. The straight, 

 narrow ribs are spaced regularly over the whorls of the shell and 

 are continuous from the base to the upper suture. They are 



