84 CLASSIFICATION OF THE ANIMAL KINGDOM. 



CLASS IV. CEPHALOPODA. 



ORDER I. DIBRANCHIATA (Cuttle-fishes). 



Sub-ord. 1. Octopoda. 



Fam. a. Octopodidse. Octopus (Poulpe), Eledone. 

 Fam. &. Argonautidse. Argonauta (Paper Nautilus). 



Sub-ord. 2. Decapoda. 



Fam. a. Spirulidae. Spirula (Post-horn). 



Fam. b. *Belemnitidse. Belemnites, Belemnitella. 



Fam. c. Sepiadee. Sepia. 



Fam. d. Sepiolidse. Sepiola, Hossia. 



Fam. e. Loliginidse (Teuthidee). Loligo (Calamary). 



Fam. /. Chiroteuthidse. Chiroteutliis, Ommastrephes. 



Fam. g. Loligopsidse. Loligopsis. 



Fam. li. Cranchiidae. Cranchia. 



ORDER II. TETRABRANCHIATA. 



Sub-ord. 1. Nautiloidea. 



Fam. a. Nautilidaa. Nautilus (Pearly Nautilus), *Litu- 



ites. 

 Fain. &. *0rthoceratida3. OrtJioceras, Cyrtoceras. 



Sub-ord. 2. *Ammonitoidea. 



Fam. a. *Goniatitidse. Goniatites, Bactrites. 



Fam. &. *Ceratitidae. Ceratites. 



Fam. c. *Ammonitid8e. Ammonites, Baculites, Scapliites. 



(Ferussac and D'Orbigny, Histoire naturelle des Cephalopodes acttabuliferes 

 vivants et fossiUs, Paris, 1835-48 ; Owen, Art. " Cephalopoda? in Todd's 

 Cyclopaedia of Anat. and Phys., 1836 ; Owen, Memoir on the Pearly Naut- 

 ilus, 1832 ; Hyatt, Embryology of the Tetrabranchiates, Bull. Mus. Comp. 



