CEPHALOPODS. 



It 



Class III.— Cephalo] \ {Cuttle-fish, Squid). 



General Characters of Cephalopods. — In these mollusks 

 (Fig. 88) the head in front of the eyes is divided into arma 

 usuall) provided with suckers; theeyesare largi . and nearly 

 terfeci 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 bjj a horny 

 "pen" I I- -. 90). 



The Cephalopods are divided into two 

 orders. Thefirsl order | Tetrabranchiata) 

 have four gills within the mantle; such 

 is th< \ Uilu8 (Fig. 91, .V. pompilius). 

 The second order, Dibranchiata, is so 

 called from having but two gills. The 

 Octopods (Fig. 92) have eight anus, and 

 the squid or cuttle-fish have ten. The 

 largest known squid is Architeuthis 

 princeps (Fig. 93); the bodj of the 

 specimen here figured measured nine 



-■ : f 



Fio 89. Pari of Ungual ribbon "f 

 Loligo Hartingii; much en- 

 larged 



Fio. 90.— Pen of 



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a. I . i i a t - 



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and a half feet from the tip of the tail to the base of the 

 arms, and was seven feet in circumference. The I i 



arms were thirty feet in length. Ordinary squids are 

 about a foot long. 



The paper nautilus [Argonauta argo) lias a beautiful 



