B. UNIVALVE Landshells. 



LIMACIDJE. 



Body an elongated slug, furnished with a shell ; 

 which is either external, and covering the lower 

 extremity of the animal ; or internal, and placed 

 behind the head of such of the naked slugs as have 

 more or less of a carinated ridge along the back. 



5. Limacellus. [I 6. Testacellus. 



V. LIMACELLUS. 



Shell oval-oblong, flat, slightly concave, entirely open, 

 without spire or pillar. 



Found in the interior of some of the land slugs, and 

 situated beneath the hinder part of the thoracic 

 disk ; generally single, but sometimes double, and 

 even triple. 



The perfect shell is only found in such of the slugs 

 as have a carinated ridge down the back, at least 

 on its lower extremity. Thus the large gray slug 

 with stripes of darker spots, is armed with this 



