BRITISH SLUGS 



1067 



although hidden beneath the skin. The 

 shell hes beneath the " shield " of the 

 slug, is oval or oblong in shape, white, and 

 shghtly concave. The concentric hnes 

 of growth demonstrate that the external 

 shell, of which it is assumed tliis is the 

 reUc. was one spirally coiled. The Lima- 

 cida is one of the groups which retain in 

 the full-grown animal the primitive shell 

 formed by the shell-gland of the embryo. 

 It is said to be the shell held by the Romans 

 to act as a charm against accident or 

 disease, called the 

 Lapis limacriim. 



On the " sliield " 

 of these slugs the 

 skin is marked by 

 fine concentric Unes, 

 a distinctive char- 

 acter that parts 

 them from the Ari- 

 onidcB family. 



A second distinc- 

 tion hes in the 

 relative position of 

 the respiratory ori- 

 fice, or breathing 

 hole, on the border of 

 the " shield," which is 

 placed behind its centre, 

 whereas the Arionida 

 have the orifice in ad- 

 vance of the centre, 

 nearer to the head. 



The third distinction 

 hes in the perfectly 

 formed shell. The class 

 is di\dded into three 

 groups : (i) Limax, (2) 

 Agriolimax, (3) Milax, 

 the two latter species 

 varying from the first - 

 named in certain im- 

 portant characteristics. 



The Limax is a highly 

 organised tribe having 

 such great power of 

 adaptability when 

 transferred to other 

 countries that the abo- 

 riginal species becomes 

 few and the Limax 

 increases its range of 

 habitat. Their existence 

 is recorded in very old 

 fossil deposits, that of 





SHELLS OF (1) LIMAX MAXIMUS, LINNE ; 



(2) AGRIOLIMAX OR L. AGRESTIS, LINNE 



(Essex). 



SHELLS OF (1) TESTACELLA HALIU- 

 riDEA, DRAPARNAUD (Surrey); (2) 

 T. SCUTULUM, SOWERBY (Surrey); 

 (3) T. MAUGEI, FERRUSAC (Ken 

 sington). 



the German Lower Miocene, which is a 

 fairly old family history for any animal 

 to boast of. 



Speaking from personal acquaintance 

 of the Limax in capti\ity. as compared 

 with the Arion, I call liim by far the 

 more interesting animal of the two. 

 There is an alert rapidity of movement, 

 a determination to remove himself 

 promptly from trying circumstances that 

 one can but respect. 



If slugs can be said to be " keen," he 

 is a keen slug ; he 

 is quick to discover 

 change of diet, and 

 never loses time in 

 discovering that 

 cooked potato or 

 carrot has been 

 placed among the 

 cabbage or lettuce 

 leaves provided. 

 The olfactory sense 

 appears to be sen- 

 si t i v e. ^^' h e n 

 handled for por- 

 trait-taking they 

 quickly recover the 

 sense of rebuff, and 

 when moved into re- 

 quired position for focus 

 from their own track of 

 escape, pertinaciously 

 set off again with a 

 strength and determina- 

 tion one hardly credits 

 the tribe with possess- 

 ing. 



The food and habits 

 of the LimacidcB are 

 exceedingly variable. 

 Some are nearly sub- 

 terranean in existence, 

 only leaving their bur- 

 rows in wet weather or 

 at night. Some are 

 practically omnivorous, 

 whilst others are purely 

 tungus feeders, all, how- 

 ever, having a lurking 

 tendency towards can- 

 nibahsm. In some 

 species there is the 

 predatory instinct dis- 

 played. In their turn 

 they are preyed upon 



