' i. \ [ON, 



I I \1 \ IK 

 CLASS CEPHALOPODA. 



II. -a. I laroe. separate from tin- h..d\. funiMied u it I. e.,mp|,-\ 



-. month with a pair of mandibles or lx mhlini: 



!' :i |i:irn1, edited with fleshy lips. ;in.| surrounded b\ :i . 

 >!' arms. 



Order I. DlBBANCHIATA. Breathing ly :i single pair of ii 

 n:il symmetrical branchi:e or u'ills. Byefl Sessile. \1 :i i.< I il.li-> 

 horny. Anns-, ei^ht or ten. furnished \vith i-<\\- ,,r acetabul 

 suckci-s. I'.ody snincliiiM-s laterally or |n.s(.i-riorly linin-d. Shell 

 internal, or none. 



Order 2. TlTRABRANOHIATA. Breathing ly tWO iair .f ! 

 elii;e. Mandibles shelly. Anns very numerous, without -iirk- 

 ers. Shell external, ehambered ; capable of ((,iii;iiiiin- tin- 

 animal. 



ORDER I. DIBRANCHIATA. 



Sub-Order 1. OcTOPODA. A rnis eiu'lit . sessile; no slu-11.* 

 Snb-Onler -2. DECAPODA. Ten arms, of which ei^ht are aeesUe, 

 and two (longer) tentacular. Shell internal. 



SUB-ORDER I. OCTOPODA. 



(Littoral.) 



Family 1. OcTOPODID^E. Mantle supported by tleshy band-. 

 \o cephalic aquiferous pores. Arms subulate, elongated. m>n- 

 or less united by webs ; their suckers sessile. 



(Pelagic.) 



Family:*. TKKMOCTOPID^: (I'm LOXK.X i D.I: ). Fmnt <>f mantle 

 supported by two buttons at, the base of the siphuncle. li' 

 into grooves on the inner side of the mantle. Aquiferm^ p 

 on the back of the head. Suckers pedunculated. 



Family:;. ARGONAUT I M.I-:. Mantle supported b\ t \\ . . buttons 

 fitting into grooves at the la^e of the siphuncle. Tin- tf 

 or dorsal arms (in tin- female only) rxp.-mdinir into v.-lan. 

 or broad webs at their extremity, from which ft] i-Il) 



*Tlio MM-alh-d external sli.-ll of the argonaut, i- the egg-nest of the 



female. 



