AMMONITES Gulielmii. 
TAB. CCCNI. 
Spec. Char. Lenticular, with a narrow front, 
radiated ; volutions exposed ; radii dissimilar, 
terminating' in small tubercles, principal radii 
furnished with two tubercles near their com- 
mencement. 
A very flat shell, bordered by two rows of tubercles 
that terminate the radii upon the edges of a flat front : 
the longer radii have each a tubercle at the commence- 
ment and another at about one-third their length, where 
they divide and alternate with shorter radii : they are all 
arched and rather acute ; the aperture is elliptical, rather 
more than one-third as wide as long. 
A very elegantly marked Ammonite ; the specimen 
retains part of its pearly shell with the coat over it : 
some of its volutions are filled with Carbonate of Lime, 
others with Iron Pyrites. Dr. W. E, Leach kindly pre- 
sented it to me some years ago . I suspect it was found 
in the clay above the Kelloways Rock. 
This elegant shell I have named after one of my oldest 
Oxford friends, Dr. George Williams, Regius Professor 
of Botany, an assiduous lover of science and every 
good, a commemoration which will, I have no doubt, 
gratify many, who, when thinking of him, will feel as I 
do a reviving pleasure and esteem. 
