M0N0C4RAPH OF BEITISH LAND AND FRESHWATER MOLLUSCA. 



71 



Limax tenellus Miiller (em. Nilsson). 



1774 Limax tenellus MUller, Verm. terr. et fluv., ii., p. 11, no. '2i0. 



1S22 — tenellus Nilsson, Hist. I\[oll. Sveeiir, p. 11. 



1S4,S — serotinus Sclirenk, Land n. Snssw. Li\ lands. 



1849 — eereiis Held, Land Moll. Bayeni, p. 15. 



IS.VJ — fiilvus Nonnand, De.sc. Limac. Nonv. , p. 7. 



IS.Vi — 'siilmitieus Duni. & Moitill, Moll. Savoie, p. 10. 



\iHyi — ehirtiis Hey)ieniann, iNLal. Bl., viii., p. 101. 



ISiiS JJn/iifo/iiiiii.r teiiellii-; Malm, Skand. Limac, p. 66, pi. iii., IF. 7-7f. 



ISOO .trinii teiirllns Letounieu.\, Moll. Vendee, p. 7. 



188:2 Agriuliiiin.e tenellus Less. & Poll, Mono.i;. Limac. Ital., p. 4.5, pi. i., f. 7. 



ISTORY. — Limax tenellm (tenellus, yery 

 slender ov delicate) wa.s first discrimin- 

 ateil by Miiller, whose name is accepted 

 by Nilsson, the obvious error in the mea- 

 surement being disregarded. 



Heynernann, however, is of oi)iui(jn 

 that Miiller's Lhmix tenellus is really 

 an Arioi), but ascribes to the tenellus of 

 jVilsson the Linmx succineus, L. ^flavus, 

 and L. cinctus, all of Midler, the L. suc- 

 cineus and L. flavus being referred to 

 the nnicolorous, and L. cinctus to tlie 

 banded form. 



He also regards the Lhmix collinus 

 Normand and the Limiix aureus Gmelin 

 as probably also referaljle to this species. 

 The late Dr. A. W. Malm, the eminent 

 Swedish naturalist, with whom the pre- 

 sent species has been associated, was so 

 greatly impressed witli its characters 

 that he instituted a new genns, Mala- 

 ccjlinui.r, for its reception, based upon 

 the soft l)ody, the tricusjiid nK'<lian-tootli, and the di-ectoconic marginals. 



Lessona & Pollunera, while adopting Malm's name of AJalacolhnax as of 

 sub-generic value, place it under Atjrioli.niax, but, as shown by iSinn-otli, it 

 is probably most correctly associated with the typical Limaces, of which it 

 is an ancient fVirm, though he places it with L. cephalonicus and L. subsux- 

 (uuis in a separate section, which he styles Microheynemann'ut to distinguish 

 it from the M((crolieiinemannia to which Limax maximus and the larger 

 species are relegated. 



Diagnosis. — Limax tenellus differs from the species to which it is struc- 

 turally most closely allied l)y its much smaller size, yellowish colour and 

 black or Ijlackish tentacles, its semi-transpa,rent shell, and yelloAv mucus. 



Internally, the reproductive organs are simple, the ]]enis-slieath is short 

 and swollen, and its retractor fixed near to and in front (jf the heart; the 

 alimentary canal is almost a counterpart of that of juvenile Limax maximus, 

 except that it pre.sents indications of a cacnm or rectatheca.' 



Original Description.— 210. LIMAX TENELr.us. Limax viiescens, capite tenta- 



ciilisnue nit;ris; lon^. 10 nnc. Totus albidus Clypeus in \\\iiiVim, ei.bdunien in vire- 



scentem colorei'n aliquantum verfjit ; ille marline postico, hoc apice snjira nigricat. 



In Fossnlis Nemoruni foliis aridis repletis ; primo vere. Miill. ,Verm. Hist. ii. , p. 



1 Monog. i., p. 284, f. 566. 



Jah}uUu^ 



,11. 



