11. Brain of the Polypus; 



a. The ring round the oeso dd. The lateral ganglions. 



phagus. 

 b. .. brain. 

 cc. .. optical ganglions. 



abdominal plexus. 



11. * Brain of the Aplysia. ' 



a. The ring round the oesophagus. 



b. .. brain. 



e. .. abdominal ganglion. 



12. The animal and shell of the Helico-Limax elongata. 



13. Janihina penicephala, with its vesicular appendage (spuma carlila- 



ginea) attached to the posterior part of the foot. 



14. Aplysia. 



a. The head. 



b. 

 c. 

 d. 

 e. 



f- 



inferior tentacula. 

 superior 

 eyes, 

 mantle. 



operculum of the branchiae. 



15. The female Sigareius seen underneath : the head and foot a little bent, 



to shew the entrance of the branchial cavity. 



a. The notch. | b. The anus. 



16. The male Sigaretus seen underneath. 



d. The anterior part of the foot cleft 



a. The notch. 

 bb. .. tentacula. 

 cc. .. foot. 



e. 



ff- 



transversely, 

 organs of generation', 

 edges of the mantle, 



17. Carinaria Mediterranea. 



18. Plectophorus with its shell. 



19. The female Vivipara taken oiit of its shell. 



a. The foot partly folded in two. 



b. operculum attached to the posterior part. 



c. .. head with the tentacula and trunk. 



d. .. little siphon prolonged under the right tentaculum. 



e. .. lateral membrane of the left side. 



f. .. edge of the mantle. 



g. A small portion of the branchia? shewing itself from underneath. 



h. The orifice of the womb and anus. 



20. Half otis, drawn from the living animal, with all its ornaments. 



r 



