ARIOPHANTA. 



27 



are well developed, the left (right in sinistral forms) divided into 

 two [a large anterior and a much smaller posterior ; in the 

 dextral forms, type solata, the left dorsal lobe is continuous, or a 

 mere slit divides it into two as in basileus]. 



In the genitalia there is a kale- sac, often of large size, which 

 receives the vas deferens ; a simple diverticulum or caecum, varying 



[Fig. 17. A. Ariophanta Icevipes. Jaw and teeth of the radula, X 300. 



B. Ariophanta immerita. Jaw and teeth of radula, X 1 55 ; and mantle- 

 edge, viewed from the outside and from below, showing the 

 dorsal lobes, X 3. 



ant.rdl. Anterior right dorsal lobe. 

 post.rdl. Posterior right dorsal lobe. 



Idl, Left dorsal lobe. 

 res.ap. Eespiratory aperture. 



pvs. Parietal side of visceral sac. 

 si. Shell-lobe. 

 pc. Pulmonary cavity.] 



in length, leads from the junction of the kale-sac and penis-sheath 

 to the retractor muscle ; the amatorial organ or dart-sac is Jong 

 and more or less cylindrical ; the spermatheca (receptaculum 

 seminis) is small, globose, and either sessile or with a short stalk. 

 Radula broad, with numerous teeth in each row : rhachidian 

 (central) tooth tricuspid, the side cusps small and basal ; the inner 

 laterals broad, bi- or tricuspid, forming a band of varying width 

 down the middle of the radula, distinct from the area occupied by 

 the outer laterals, which are elongate and uni- or bicuspid and 



