90 
PALEONTOLOGY OF NEW-YORK. 
481. 1. CYCLONEMA CANCELLATA. 
Pl. XXVIII. Fig. 1 a - g. 
Liltorina cancellata. Hall, Geol. Rep. 4th Dist. N. York, 1843, pag. 72 and 73, figs. 5 and 6. 
Obliquely sub-conical or globose, with a short spire; volutions about four, rounded, rapidly 
increasing from the apex so that the last one occupies almost the whole bulk of the shell; 
aperture scarcely expanded ; surface marked by prominent threadlike lines, coincident with 
the spire, which are decussated by finer elevated striae in a slightly oblique direction. 
The size of this shell varies from the most minute form, as in 1 a, to the largest figure 
represented. In young shells the decussating striae are usually well preserved, while they 
gradually become obsolete in older specimens, which are likewise frequently distorted by 
pressure. 
Fig. 1 a , b , c, d. Views of several specimens, showing an increasing size and slight variation 
in form. 
Fig. 1 e. View of the aperture, the shell being slightly compressed in a vertical direction. 
Fig. If, g. View of the front of the shell, and aperture of the same. 
Position and localities. This species is quite abundant in the lower green shale at Sodus, 
Wayne county, and occurs in other localities between that place and Rochester, where it is 
found in the upper green shale. ( state Collection.) 
482. 2. CYCLONEMA VENTRICOSA (». sp.). 
Pl. XXVIII. Fig. 2 a, b, c. 
Shell ventricose, sub-conical; volutions about three, rapidly enlarging from the apex ; mouth 
of the size of the last volution ; surface marked by strong elevated sub-imbricating striae 
parallel to the direction of the volutions. 
This shell resembles the last, but it is more elongated and the striae parallel to the volutions 
are very sharp and distinct, with obsolete decussating striae. The shell is also larger than is 
usual for the preceding species, and has one volution less. 
Fig. 2 a. Front view of the shell. 
Fig. 2 b. View of the mouth. 
Fig. 2 c. A portion of the surface enlarged, showing the character of the striae. 
Position and locality. In the low T er green shale, Sodus, Wayne county. 
483. 3. CYCLONEMA'? OBSOLETA (». sp.). 
Pl. XXVIII. Fig. 3 a, b. 
Sub-globose or ovoid; volutions scarcely three, the last one occupying almost the entire 
bulk of the shell; spire scarcely elevated, consisting of less than two minute whorls; mouth 
oval oblong; surface finely striated transversely to the direction of the volutions. 
