212 ZQOELO GM 
angle, and describe it as it swims, with its foot and mouth 
anterior, the visceral hump posterior, the mantle cavity ventral, 
Fic. 124, 
A. Loligo vulgaris. B. Pen of the same, reduced in size. *f 
a. Arms. D. View of the head from in front, show- 
t. Tentacles. ing the arms (a), the tentacles (¢), the 
C. Side view of one of the suckers, show- mouth (m), and the funnel (/). 
ing the horny hooks surrounding the 
margin, 
and the shell or cuttle-bone, which may be felt through the 
skin, dorsal. The most dorsally-placed pair of arms, really the 
most anterior, are termed the first pair. 
Sepia, being a Decapod, has five pairs of arms, of these, 
the fourth pair are unlike the others, They are much longer, 
