SYNOPTIC TABLE 



Fteropoda, 



Gasteropoda. 



No foot for crawling ; no f 

 arms for dragging orj 

 sftizin/r nrpv. Twn fins./ 



seizing prey. Two fins, ( Shell ensheathing ; of one 

 alike and opposite, for[ 

 swimming. 



Body straight, never spiral 

 or with a shell capable j 

 of containing it ; a mus- 

 cular foot united to the< 

 body in its whole! 

 length, placed under] 

 the belly, for crawling. 



Shell without columella or 

 operculum ; not forming 

 a complete spire, unless 

 rolled 



TnACHELrOD A 



Greater part of the body 

 twisted in a spire, sepa- 

 rate from the foot, and | Shell always spiral, whorls 

 always enveloped in a/ generally numerous, with 



spirivalve shell ; foot 

 free, flat, attached to 

 the inferior base of the 

 neck, for crawling ,. . 



either a columella or an 

 operculum . . 



Cephalopoda.. 



I Lower part of the body 

 contained in a mantle 



f rn V' Shell regularly multilocu- 



formed likeabag jhead { « .J unilocul 



projecting lrom this 1 



bag, crowned by arms, 

 not articulated, furnish- 

 ed with suckers sur- 

 rounding the mouth ; 2 

 horny jaws 



whorled in the same 

 plane ; the spire entering 

 into the mouth or in- 

 clining towards it. 



