ZOOLOGY. 583 ' 



sacciform, provided with arms or fins, and mostly with 

 eyes upon a kind of head. 



These animals have the mouth situated above or in 

 front of the body, and are distinctly separated into 

 mantle and abdomen, while they are frequently sur- 

 rounded by a shell. They have a kind of head with 

 tentacles or arms, and frequently furnished with eyes 

 like the Snails, or pretty nearly like the Fishes; the 

 sexual parts united and separated. They ah 1 row, paddle, 

 or steer themselves about in the sea. 



Fam. 5. Snail- Kracken Pteropoda. 



Body mostly gelatinous, sacciform, closed all round 

 and free ; fins upon the sides of the neck, with two ten- 

 tacula frequently projecting from near the mouth ; an- 

 drogynous, naked, and inclosed within a shell. 



These transparent animalcules swim about upright in 

 the sea, and wave the fins in this position as rapidly as a 

 butterfly does its wings. Most of them are covered with 

 a spathiform and likewise transparent shell. The bran- 

 chiae are placed externally on the body, but are not very 

 distinct. Several species have an appendage in front of 

 the neck, which is obviously a rudiment of the Snail's 

 pad or sole Fluyelkracken. 



The Heteropoda appear to resemble the Plantar or 

 Sole- Snails, but the body is mostly gelatinous, and the 

 foot or sole is only compressed to form a fin, so that they 

 can only swim but not creep with it. Many of them 

 have a shell almost like that of the Argonaut a. Ptero- 

 tracheae Buderkracken . 



Fam. 6. Typical Kracken, Cephalopoda or Sepia. 



Muscular animals inclosed within a sacciform mantle, 

 open in front ; head furnished with eyes, and surrounded 

 by more than four strong prehensile arms ; laminated or 

 leaf-like branchiae within the mantle, sexes separate ; in the 

 body is a nephroidal or kidney-like gland, which secretes 

 a dark-coloured or inky fluid, on which account they are 

 called by us ' Dintenschnecken' Stcmkracken. They are 

 obviously the highest organized Malacozoa, and already 

 remind us strongly of Fishes, partly from their size, 



