93 
MUREX. 
A. Spinous, with a produced beak. (Plate 
xvni. Fig. 1.) 
B. Having longitudinal sutures, or varices, ex- 
panding into crisped foliations ; beak ab- 
breviated. (Fig, 2.) 
C. With thick protuberant, rounded, sutures; 
varicose. (Fig. 3.) 
D. More or less spinous, and without any beak. 
(Fig. 4.) 
E. Unarmed with spines, and having a long, 
straight, subulate beak, (Fig. 5.) 
F. Tapering, with a long spire and short beak. 
(Fig. 6.) 
G. With a toothed columella, (Plate XXIII. 
Fig. 2.) 
Shell univalve, spiral, often formed with longi- 
tudinal membranaceous sutures. Aperture termi- 
nating in a canal either straight or turned up 
backwards, and not inclining either to the right 
or left. 
