PULMONATA. 



163 



Limas, Cuvier, R. A. ed. 2. 



Voigt, iii. 41. 

 Limacias, Rajln. Anal. Nat. 1815. 

 Limacella (shell), Brard, Coq. Paris, 1815, not Blainv. 

 Limacellus (shell), Turton, Manual, ed. 1. 1831, not Blainv. 

 ? Pannacella (nigricans), Fhilippi, Moll. Sicil. 

 Megaspis, Krynick. MSS. ined. ^ 



KrjTiickia, Kaleniczenko, Bull. Soc. Moscou, 1839, p. 30, not 



described. 

 KrjTiickelhis, Kaleniczenko, Bull. Soc. Moscou, 1851, i. 215; iti 



Arch. Naturg. 1852, p. 288. 



Dr. John Kaleniczenko {Bull. Soc. Imp. Nat. Moscou, 1851, 

 p. 215) describes a new genus of Russian slugs under the name 

 of Krynickellus, because " le bouclier est libre dans sa partie 

 anterieure jusqu'a I'oriiice respiratoire, caractere qui la distingue 

 des Arions et des Limaces." In this and all the other characters 

 which are given, it agrees with Limax cinereus, variegatus, and 

 all the species of the true Limacince that have been hitherto de- 

 scribed. 



The Slugs (Limax) sometimes suspend themselves by a kind of 

 thread formed from the viscid secretion which covers their bodj^ ; 

 hence one of the smaller ones has been called Limax filans. 



The shell of the Slug {Limax) is covered with a distinct pe- 

 riostraca. It has generally been believed that shells which are 

 covered with a reflexed portion or imbedded in the mantle are 

 destitute of this covering, and they have been separated from 

 other shells for this reason. 



This is an error arising fi-om the theoiy that the periostraca 

 of shells is analogous to the scarf skin (cuticle) of vertebrated 

 animals, instead of its being merely the part consisting almost 

 entirely of animal matter that is first deposited by the animal 

 when it is about to enlarge its shell, and which forms the basis 

 of the new part of the shell afterwards strengthened. 



* Mantle elongate, produced behind, 



1. Limax cinereus. B.M. 



Grey, spotted ; dorsal keel acute, elongate, white ; tentacles 

 grey or brown ; shield pointed behind ; respiratory hole poste- 

 rior. Shell thin, concave. 



Limace cinereo-nigricante, Aldrov. iv. 702. 

 Limax cinereus. Lister, Phil. Trans. 1674, ix. 96. t. 14 ; Anim. 

 Angl. 127. t. 5. f. 6, 7, 9, 10 ; Synops. t. 102-105. 

 Muller, Verm. ii. 5. 



