437 



LIMAX. 



LIMAX. 



438 



Shell null, there being neither rudimentary internal shell nor 

 calcareous concretion. (Rang.) 



V. Taunaiti (Onchidium lave, Blainville), may be taken as an 

 example. 



Taginului. 



a, the animal contracted (under Bide) ; t>, the animal extended and in pro- 

 gression. 



The genus Vaginvlug is found in East and West Indies, if. Rang, 

 who remarks that they have been said to be both terrestrial and fresh- 

 water, states that he never met with them in Bourbon and Martinique, 

 except in the woods and gardens under old fallen trunks. 



There is great confusion about the nomenclature of Onchidnm, 

 Peronia, Veronicclla, and Vayinulus. Cuvier observes that Vaginulua 

 is different from Onchidium, with which M. De Blainville has united 

 it, at the same time that he has detached the true Onchidia, to form 

 his genus Peronia. It appears in fact, as M. Deshayes observes, that 

 M. De Blainville has made of the marine Onchidia of Cuvier his (De 

 Blainville's) genus Peronia, which he places ill his family Cyclo- 

 Iranchiata near Dora, and that he collects the fresh-water species 

 under the genus Vaginulut, to which he unites his genus Veronicella, 

 which last he has himself rejected. 



Limacella (De Blainville). Animal elongated, sub-cylindrical, pro- 

 vided with a foot as long and as large as itself, from which it is 

 separated only by a furrow ; enveloped in a thick skin, forming at the 

 anterior part of the back a sort of buckler for the protection of the 

 pulmonary cavity, the orifice of which is at its right border; the 

 orifices of the generative apparatus distant, that of. the oviduct at the 

 posterior part of the right side, and communicating by a furrow with 

 the termination of the male organ, situated at the root of the right 

 tentacle. 



L. Elfortiana is a good example. 



Limacella Elfortiana, 



Limax. Animal oblong, more or less elongated, demi-cylindrical, 

 furnished with a cuirass at the anterior part; head sufficiently 

 distinct, retractile under the cuirass, carrying two pairs of tentacles 

 equally retractile, terminated in a rising (bouton), the upper pair long 

 and oculiferous, the lower pair short ; foot great and oblong, the 

 pulmonary cavity situated under the cuirass, and opening under its 

 right border ; orifice of the anus at the posterior border of that of 

 the respiratory cavity ; organs of generation united and showing them- 

 selves at the right side anteriorly, near the great tentacle ; sometimes 

 a terminal mucous pore. A rudimentary internal shell, or calcareous 

 concretions in the thickness of the cuirass. 



Such is the general definition of Limax by M. Rang. He observes 

 that M. De Fcrussac seized on certain anomalies in the characters of 

 these molluscs, which led the latter to separate a certain number, 

 out of which he forms his genus Arion. M. Rang observes that this 

 distinction has not been adopted by M. De Blainville, excepting for the 

 establishment of two sections ; but M. Rang thinks it better to form 

 the whole into two sub-genera, namely, Arion, Ferussac, and Limaj; 

 the latter consisting of the slugs properly so called. 



M. De Blainville divides the genus Limax into four sections : the 

 1st consisting of those species in which the pulmonary orifice is very 

 anterior, the tail carinated, and the rudiment of the shell moat 

 evident. This section consists of the Gray Slugs ; Limax grisew is 

 given as an example. 



The 2nd section consists of species whose pulmonary orifice is more 

 posterior; the tail not cariuated, hollowed at its extremity into a 

 blind sinus, and the rudiment of the shell granulous. This section 

 consist* of the Red Slugs (genus Arion, De Fdrussac). The example 

 given i L. rufut. 



The 3rd section consists of species whose buckler is not distinct, 

 and which have the ocular tentacles club-shaped, and the others lateral 

 and oblong (genus Philomique of Rafinesque). The example given is 

 L. Ojcyurtu. 



The 4th section comprehends those species whose buckler is not 



distinct, and which have the two pairs of tentacles cylindrical, nearly 

 on the same line, the smaller ones being between the greater (genus 

 Eumeles, Rafiuesque). The example given is L. nebidosus. 



The two last sections are not noticed by M. Rang ; and Cuvier is of 

 opinion that the two genera recorded by M. Rafinesque are too im- 

 perfectly indicated to be admitted into his (M. Cuvier's) work. M. 

 Rang also declines to admit them till there is more information on 

 the subject. 



Sub-genus Arion. Respiratory orifice situated comparatively for- 

 ward, towards the anterior part of the buckler, which is rough 

 (chagrinee) and contains small calcareous concretions. There is a 

 terminal mucous pore. 



A. rufui, De Fe"r., Limax rufus, Linn. This species ia sometimes 

 nearly quite black. 



Bed Slug (Arion t-w/iu). 



Sub-genus Limax. Respiratory orifice situated comparatively back- 

 wards ; the buckler is marked with fine and concentric striae, con- 

 taining a testaceous rudiment which is solid but without any volutatory 

 impression. There is no terminal mucous pore. 



L. antiquorum, De Fe"r., L. maximus, Linn., Gray Slug. 



o 



Gray Slug (Limax antiquorum, De F6r. ; Limax maximvi, Linn.). 

 a, internal shell ; , the same enlarged ; c, internal view of the shell from 

 another individual. 



The geographical distribution of this genus is very wide ; but the 

 northern and temperate countries of both continents seem to be 

 plagued with a greater number than those of the torrid zone. They 

 are found in Africa, and have been noticed at each extremity of that 

 quarter of the globe. Messrs. Quoy and Gaimard describe some 

 from Australia, and M. Rang saw them in India and in the island 

 of Mauritius. 



The species of this genus can hardly be of any direct utility to man, 

 with the exception of the supposed virtues of a decoction or ' bouillon ' 

 of Red Slugs in disorders of the chest, whilst the injury which they 

 inflict on the garden and the field is most devastating, notwithstand- 

 ing the number of birds which prey upon them. Gardeners are con- 

 stantly racking their invention to free themselves from these devouring 

 hosts. Quicklime, soot, fine coal ashes, and saw-dust have been used 

 as defences for young and tender plants. The virtue of the first is 

 soon exhausted and the slugs do not care much for the second after 

 a while, but if the soot be plentifully and frequently renewed it will 

 keep them away in great measure. Coal-ashes, not too coarse, a_ud 

 saw-dufci annoy them by sticking to their foot and impeding them. 

 A stout coarse horsehair line, such as is used for hanging clothes out 

 to dry, coiled round the stems of wall fruit-trees and stretched along 

 the wall, will operate as a protection to the fruit from both snails and 

 slugs, in consequence of the bristly surface presented to them, and 

 which they shrink from encountering. Care must of course be taken 

 that they do not get under it. Watering evening and morning with 

 strong fresh lime-water is said to have a good effect, for it penetrates 

 about the roots of the plants and into the earth, where they lie hid. 

 Thin slices of any vegetable of which they are more fond than of the 

 crop to be protected will allure them, and they may be thus killed by. 

 scores early in the morning by dividing them suddenly with a sharp 

 instrument. The dead bodies should be left on the spot as a bait, 

 for we have seen the living slugs preying upon the exposed bowels of 

 the dead ones, most probably attracted by the half digested vegetable 

 matter. Ducks destroy great numbers of these pests, whilst they 

 improve themselves, but they are apt to trample down a young and 

 delicate crop of vegetables. 



M. Deshayes, in his edition of Lamarck, remarks that the great 

 genus Limax is not so easy to study as might be supposed ; the 

 colour of the species is easily modified, and everything leads to 

 the belief that they have been multiplied by those authors who have 

 attached too much importance to these characters. M. Deshayes 

 presumes that the European species are less numerous than some 

 naturalists suppose. In passing from the north to the south the 

 Limacet undergo modifications similar to those undergone by other 

 Molluscs ; and when we have under our eyes a series of modifications 

 impressed upon a species which has lived under different circumstances 



