BOOK TENTH. 



CEPHALOPHORA 



CLASSIFICATION. 



§ '^01. 



The organization of the animals composing this class is quite dissimilar; 

 and, as in the preceding class there were species which approached the 

 Zoophytes, so here there are those which are scarcely above the Worms. 

 Thus, it is a question whether the genus Sagitta, which is placed at the 

 head of this class, is really in its right place, although all the attempts to 

 place it in another group have furnished results no more satisfactory. 



Then again, it may be objected that the name Cephalophora should have 

 been given to a class composed of the Pteropoda, Heteropoda, and Gastero- 

 poda, since it belongs equally well to Cephalopoda ; but I have adopted it 

 for the sole reason of being unable to find a better.*" 



The sub-order Apneusta with its two families Anangia and Angio- 

 phora, has been established by KclUker in opposition to the other Gastero- 

 poda, which have distinct respiratory organs.*-* This division, composed 

 of small and very interesting species, is the more admissible since it is 

 based upon the anatomical structure of these animals ; and also as the 

 most recent investigations have shown that the term Phlebenterata used by 

 Qiiatrefages, is improper. 



ORDER I. PTEROPODA. 



Animals with natatory organs composed of wing-like or fin-like cutane- 

 ous lobes, symmetrically arranged upon the two sides of the body. 



1 Meckel (Syst. der verKleich. Anat.) has al- He has placed these, with those which Quatre- 



rtady used tliis word in the same way. fa"^^ has described under the name of Phleben- 



'^ Kiillikcr lias coramunicated to me a yet un- terata, in the division of Apneusta which he 



published work in which he has described, beside divides into two sections : 1. Angiophora, having 



F/aie/Zf/ia and Po/ycera, three new genera of the a heart and rudimentary vascular system. 2. 



inferior Gasteropoda, under the names of Acan- Anangia, without either heart or vessels. 

 thhm, Lissosoma, and Rhodope 



