MOLLUSC A OR UNIVALVES. 159 



ing four tentacula ; it 

 is doubtful whether it has 

 eyes ; foot large. — There 

 are 11 recent species. 



This animal resembles 

 the Aplysia exceedingly, 

 but has a more ample 

 mantle ; it inhabits tranquil bays in India, and 

 the Isle of France. 



Family 8. — Lirnacidce* 



This family, like the last, has a very slightly 

 developed shell, forming merely a covering for 

 the branchiae, and into which the animal is 

 unable to enter. All the genera are terrestrial, 

 breathing air, but preferring moist places to 

 those perfectly dry. There are five genera, 

 two of which do not possess shells, although 

 they have a substance protecting the organs of 

 respiration. 



33. Onchidium. — Shell none. Animal, 

 long; head with four tentacula; foot long. Found 



* Les Limaciens, Lamarck. 



