VUl INTRODUCTION. 



Ganglioneura Rudolphi, Bcitr. z. Anthrop. 1812. 



Malacosia Rufncsque, Anal. Nat. 40. 1815. 



Apalosia Rafinesque, Prec. Som. 12. 1814. ; Anal. Nat. 137. 1815. 



Brachiopneusta Fischer. 



Malacozoa (Les Malacozoaires) Blainv. Journ. Phys. 1816; Man. 



Malac. 362. 1825 ; Bronn, Gesch. de Nat. hi. 1847. 

 Malacozoaria Blainv. Diet. Sci. Nat. xxxii. 171. 1824. 

 Gasterozoa Cams, Ueber Thierr. 1826; Oken, His. 1828. 

 Dermatozoa Filzinger, Syst. Rept. 8. 1843. 

 Mollusques or Malacozoaires Blainv. Bull. Soc. Philom. 1816, 



12. 2. 

 Mollusca or Cyclogangliata Grant, Outlines, Lectures, 1833, 17. 



Synopsis of the Classes. 



A. Animal crawling on a Foot placed under the Body. — Pe (lifer a. 



I. Gasteropoda (Gasteropodes}. Head distinct, furnished with 

 eyes and tentacles, and usually protected by one large 

 conical valve, the other being rudimentary or abortive. 



II. Conchifera {Conchifers~). Mouth placed between the gills ; 

 they and the body being enclosed between the two large 

 leaves of the mantle, which are covered with two equal or 

 subequal valves, united along the back by a cartilage. 



B. Animal destitute of a Foot, or with only a rudimentary one. — 



Apoda. 



III. Brachiopoda (B?-achiopodes). Mouth placed at the base of 

 two spirally twisted ciliated arms, between the two leaves of 

 the mantle, which are covered with two separate shelly 

 valves. They live attached to other marine bodies. 



IV. Pteropoda (Pteropodes). Head prominent, with one or two 

 pairs of fins on the side of the neck, by which they move 

 about in the ocean. Body often covered with a thin, glossy, 

 conoidal shell. 



V. Cephalopoda (Cephalopodes). Head large, distinct, furnished 

 with eight or ten or more arms, by means of which they 

 head downwards. 



