GASTEROPODA OF THE LOWER GREEN MARLS. 147 
and only a small portion of the shell substance remains. The spiral lines 
are usually distinct, but the minute transverse lines of growth which ought 
to mark the surface are only occasionally seen. The species has apparently 
reached a pretty large size, one individual having a length of considerably 
more than 3 inches, and is imperfect at each end. Dr. Morton’s figure 
given in the Synopsis is more rapidly tapering tnan any of the examples I 
have seen. Among the specimens borrowed from the collection at Phila- 
delphia there is a fragment which I supposed to be the one used and figured 
by Dr. Morton. It is compressed to less than one-half of its original diam- 
eter and is probably correspondingly increased in its rate of expansion, which 
will in part account for the outline of his figure. The specimen is much 
injured and is probably less perfect than when Dr. Morton used it. I have 
attempted to give a figure of it as it now is as a record of its existence and 
condition, as it will in all probability entirely decompose in a few years. 
Formation and locality: Dr. Morton gives only New Jersey and Alabama 
as localities. His New Jersey example is probably from Upper Freehold, 
from whence I have several examples. Others are from near New Egypt, 
Tinton Falls, J. Banks’s pits near Marshallville, and from J. S. Cook’s beds 
near Tinton Falls, New Jersey; all from the Lower Mazrls. 
Genus LAXISPIRA Gabb. 
Proc. Acad. Nat. Sci., Phila., 1876, p. 301, Pl. xvu, Figs. 6, 7. 
Mr. Gabb’s description of this genus is as follows: “Shell spiral, dextral, 
whorls with a circular cross section, few in number, and so rapidly descend- 
ing as to form an open spiral; aperture simple, lips thin.” 
His remarks on this genus are as follows, given in full: 
A curious genus, the relations of which are not clear to me. I propose it to 
receive some shells which have been long known as internal casts in the marls of 
New Jersey, but of which the surface was unknown until quite recently. In gen- 
eral form they might be compared to a partially uncoiled Turritella. From that 
genus they differ, however, in the whorls not being in contact, and from Vermetus 
and the allied genera in being regular spirals, but not having the apex either tur- 
ritelloid or attached. Another analogy, though perhaps only one of external 
resemblance, might be adduced in such shells as Huomphalus circinalis Goldf., or 
in some of the Delphinulas. 
