CEPHAL0P0D8. 
76 
Class III. — Cephalopoda {Cuttle-fish, Squid), 
General Characters of Cephalopods. — In these mollusks 
(Fig. 88) the head in front of the eyes is divided into arms 
usually provided with suckers; the eyes are large, and nearly 
as perfect as in fishes. The brain is large, and with the 
other important nervous ganglia lodged in the head and 
protected by pieces of cartilage. The mouth-cavity (phar- 
ynx) is armed with two teeth like a par- 
rot's beak, besides a lingual ribbon (Fig. 
89). The body is supported by a horny 
^*pen" (Fig. 90). 
The Cephalopods are divided into two 
orders. The first order ( Tetrairancliiata) 
have four gills within the mantle; such 
is the Nautilus (Fig. 91, N, pompilius). 
The second order, DiirmicMata, is so 
called from having but two gills. The 
Octopods (Fig. 93) have eight arms, and 
the squid or cuttle-fish have ten. The 
largest known squid is ArcMteutJiis 
princeps (Fig. 93); the body of the 
specimen here figured measured nine 
Fig. 89— Part of lingrual ribbon of 
Loligo Hartingii; much en- 
larged. 
Fig. 90.— Pen of 
Loligo pallida^ 
dorsal side ; nat- 
ural size. 
and a half feet from the tip of the tail to the base of the 
arms, and was seven feet in circumference. The longer 
arms were thirty feet in length. Ordinary squids are 
about a foot long. 
The paper nautilus {Argonauta argo) has a beautiful 
