TO GEOLOGY. 113 
/l. elevatus. Plate 4. Fig. 98. 
Description. Shell subulate, polished, furnished with a 
single transverse furrow near the middle of the whorl; sub- 
stance. of the shell rather thick ; spire very much elevated ; 
suture furrowed ; columella with one large and one small 
fold ; whorls flattened above the medial furrow ; mouth ob- 
lique, subovate ; outer lip simple. 
Length... . Breadth .2, of an inch. 
Observations. This interesting species differs from any 
with which I am acquainted. The specimens I have been 
able to examine (three) are all more or less broken. The 
best one which is here figured is broken at the top, six 
whorls only remaining. It most probably had about ten. 
At first view of the mouth, the large fold only wotild be ob- 
served. More irtternally, and below it, a very minute one 
may be seen with the aid of the miscroscope. In one speci- 
men this lower fold appears to be disposed to separate into 
two—other individuals may show this character more 
developed. 
Al. melanellus. Plate 4. Fig. 99. 
Description. Shell subulate, smooth ; substance of the 
shell rather thick ; spire elevated, pointed ; suture sharply 
impressed ; columella with a single large fold ; whorls six, 
flattened ; mouth ovate, outer lip simple. 
Length 7-20ths, Breadth 3-20ths, of an inch, 
ip 
