SPECIAL ANATOMY. Oj^J 



and the pedal disk, at the side of the pulmonary orifice. 

 The salivary glands are arborescent, or fasciculated in 

 appearance. The ducts are short and delicate. The 

 lobuli of the liver are looser, or more separated, than in 

 the preceding genera. 



Helix. The buccal body has the same appearance, 

 generally, as in the slugs. The retractor muscle is 

 much stronger, and has its origin in common with the 

 retractor of the foot and tentaculse, from the columella of 

 the shell ; at its insertion it forms a semicircle around the 

 posterior inferior part of the buccal body. The pouch of 

 the lingual lamina is always a prominent object. In H. 

 cellaria and H. coneava^ihe buccal body is proportionately 

 nearly twice the length of that of the other species. The 

 dental plate varies in some degree in different species : in 

 H, ligera, H. intertexta, &c. it is smooth anteriorly, and 

 in the middle projects downwards into a large, conical 

 toothlet ; in H. albolabris, H. tridentata, &c. the ante- 

 rior surface presents a number of curved ridges, each of 

 which projects inferiorly as a sort of toothlet. 



The oesophagus is generally long and narrow. In 

 some species it is unusually long and contracted, as in 

 H. concava, R. cellaria, H. hirsuta, IT. perspectiva, etc. ; 

 in others it is long, and dilated in the middle, as in S. 

 aurieulata ; in many it is capacious, and gradually passes 

 into the stomach, as in M. exoleta, etc. 



The stomach is usually cylindroid, and more or less 

 sacculated. The posterior cul-de-sac is always present. 



