118 PNEUMONOBRANCHIATA. 



Fer. Tab. 23. ; Johnst. Rep. Berw. Nat. Hist. 

 CM. 



Inhab. shady woods, and is comparatively rare in 

 Berwickshire. 



Dr. Johnston observes, that this differs from every 

 variety ofLimax agrestis in its darker colour, its colour- 

 less mucus, in the abrupt termination of the tail, in 

 the position of the shield, which is nearly central 

 when the animal is fully extended, and in the size of 

 the shield, which is as long as the posterior half of the 

 body ; nor is there any keel on this part. 



Dr. Johnston adds, that, as a native, its discovery 

 is due to his friend Mr. J. Alder of Newcastle, who 

 pointed out its peculiar character to him in specimens 

 taken in Dunglass Dean; and Mr. Alder thought it 

 was the Limax brunneus of Draparnaud. 



Draparnaud discovered his specimen near Mont- 

 pellier, and Ferussac arranges it with those species of 

 which he is desirous of receiving further information : 

 indeed, he appears to doubt to which genus it ought 

 to be referred. 



B. Mantle shield-shaped, with a partly external, 

 thin, central, spiral shell. (Vitrinina.) 



8. 2. VITRINA. (Bubble Shell.) 

 Animal Body rather elongate, lanceolate; mantle 

 subanterior, produced into a rugose shield in front, 

 with a central spiral prominence, protected by a 

 thin, transparent, rather depressed, subglobular 

 shell, which is partly covered by the back edge of 

 the shield, and a tongue-like process of the mantle 



