80 collinge: a review of the arionid.^ of the British isles. 



d — annoricana, Pollonera. Recorded by Mr. Cockerell (6) from 

 Sturminster Marshall, Dorset. 

 The known varieties may be classed as follows : — 



Arion fasciatus, Nils. 

 No keel in adult. Keel present in adult. 



v. neusiriacus, Mab. (brown). -\ v. neusiriacus, Mab. (Continental 

 v. flavescens, Cllge. (yellow). form). 



v. griseus, Cllge. (silver-grey). J f v. miser, Poll. 

 v. annoricana, Poll. ' I Not found in the British Isles. 



Geomalacus, Allman. 



Body sub-cylindrical ; mantle and upper portion of the body 



black or very dark grey, spotted with yellow, these markings 



forming more or less interrupted stripes ; head and tentacles 



dark grey; sole light yellow; foot-fringe brown with transverse 



lineoles ; rugoe long and closely set ; respiratory orifice at the 



front of the middle of the mantle ; genital orifice at the base 



of the right lower tentacle ; mucous gland at the posterior 



extremity of the body, opening by a transverse slit ; shell 



solid. 



This genus was established by Allman (i) in 1846. It resembles 



the genus Arion in having a caudal gland, which, however, opens 



transversely and not longitudinally as in the former genus. The 



genital orifice lies behind the base of the right lower tentacle, thus 



resembling the Limacidce. There is a solid internal shell, not unlike 



that found in Limax. 



There is but one species found in the British Isles, and that 

 occurs in Ireland only. It also occurs in the north-west of Spain 

 and in the north of Portugal. Much rubbish has been written 

 about the genus by French malacologists, which many years ago 

 induced Dr. D. F. Heynemann to reply to the various observations 

 in a masterly paper (20-2 ia). 



Geomalacus maculosus, Allman, 1846. 

 Body a glossy brown or deep grey, the mantle and back being 

 spotted with a series of yellow or yellowish-white markings 

 which are often close and regular enough to give it the 

 appearance of longitudinal bands ; head and tentacles dark 

 grey ; sole yellowish-white. 

 This interesting slug was discovered by Mr. William Andrews in 

 the autumn of 1842, "on rocks around Lough Carrough, to the 

 south of Castlemain Bay, Co. Kerry, in the west of Ireland." It 

 was described by Allman in 1846. 



