(SC = 
PLATE XIX. 
. Strombus pugilis. 
. Murex saxatilis. 
. Halyotis vulgaris, its shell taken away, seen on the back, and the edges 
of the branchial cavity put asunder. 
A. The large muscle which attaches the animal to the shell. 
a. The anus. | c. The viscous organ. 
bb. ... branchie. | d. .. heartin its pericardium. 
. Halyotis, etc. the pericardium and branchial cavity opened. 
A. The large muscles above. d. The heart. 
SAA. . ARIS e. .. right auricle. 3 
bb. .. branchiz. fo... leftianriele: 
c. .. viscous organ. 8. heart surrounding the rectum. 
wz. .. branchial arteries. 
. The beart and large vessels magnified. 
a. t. As the preceding figure. 
h. The right branchial vein. 
