286 Mr. W. E. Collinge on the Variety 



XLVIII. — On the Variety cinereo-niger, Wolf, of Limax 

 maximus, L. By Walter E. Collinge, Demonstrator 

 of Biology in Mason College, Birmingham. 



In the 'Annals' for March Mr. Roebuck objects to my 

 classing the Limax cinereo-niger j Wolf, as a colour-variation 

 of the well-known L. maximus, L., and puts forward an 

 argument for the retention of this slug as a distinct species or 

 subspecies. 



He contends that it differs from L. maximus in its " den- 

 tition," the anatomy of the reproductive organs, and in its 

 external form and coloration. When I stated * that there 

 were no differences of importance in the general anatomy, I 

 did not think it necessary to enter into details as to the slight 

 variations and modifications to which all the Mollusca are 

 subject, according to age, season of the year, habitat, &c., 

 for both Simroth f and Scharff | had previously described the 

 anatomy, and I stated that my investigations agreed with 

 the accounts given by them. 



It seems, however, since Mr. Roebuck has become con- 

 vinced that he was wrong in stating that there were important 

 differences in the reproductive organs, solely upon the obser- 

 vations of Sordelli §, that he now intends to uphold its 

 specific distinction upon some drawings &c. made by Mr. 

 Charles Ashford which exhibit some slight variations from 

 one another, and upon some observations on the lingual 

 ribbon. 



The lingual ribbon, which Mr. Roebuck regards as of such 

 importance, is, for generic or specific distinction, of little or no 

 value ; indeed, such is its unreliability that not a few mala- 

 cologists totally ignore it. 



Simroth, who has had more experience with the anatomy 

 of the slugs than any other living investigator, years ago 

 showed the great variation it was subject to, and that it " was 

 perhaps the most unsuitable portion of the slug^s body " that 

 could have been chosen for purposes of classification. Indeed 

 a large number of species constituted upon differences in the 

 lingual ribbon he conclusively proved by a series of careful 

 anatomical investigations to be but varieties of L. maximus, 

 whose lingual ribbon is subject to endless variations. The 



* Ann. & Mag. Nat. Hist. 1892, vol. x. p. 425. 

 t Zeitschr. f. wiss. Zool. 1885. vol. xlii. 

 X Trans. Royal Dublin Soc. 1891, ser. 2, vol. iv. p. 518. 

 § I tliir.k Mr. Roebuck's statement " important differences" is hardly 

 borne out by Sordelli's original account. 



