22 THE NAUTILUS. 



ton (1831) kept the name for the shells of Limax and allied genera, though 

 spelling it Limacellus. We are told, for instance, that Liniacellus parma, 

 Brard, is " found m the Limax maximus^^ as though it were a sort of 



parasite I 



(5) I think it nearly certain that my Liiiiacella nebulosa is Rafinesque's species 

 E. nebulosus ; but if so, of course that author described it incorrectly. Mr. 

 Pilsbry will observe that I have given the reference with a query. 



While on the subject, it may be well to mention that there is a figure and At- 

 scT\}pX\onoi Limacella lacti/ormis [as Eifortiana) in Knight's ' Pictorial Museum 

 of Animated Nature,' vol. ii. and fig. 2598. The figure is very bad, being a rough 

 copy of that in Man. de Mai.; but the generic description, so far as it goes, is 

 accurate. T. D. A. Cockerf.ll. 



3 Fairfax Road, Bedford Park, Chiswick, W., 

 February 3, 1891. 



Article IV. By H. A. Pilsbry. 



In concluding I wish simply to emphasize a few points upon 

 which both Mr. Cockerell and myself have already touched. 



(1) That Blainville's figures are so poor that Mr, Cockerell could 

 not tell his Veronicella from his Limacella, but repeatedly confused 

 them in his first article. Blainville's description most certainly 

 indicates Vaginulus rather than Tehennophorus, as anyone can see 

 by reading the translation of it given in my article. We can allow 

 for some inaccuracy in descriptions by early authors, but we cannot 

 suppose that when they say " black " they mean " white." 



(2) As to Limacella, Brard. The name as used by Brard covers 

 species of both Limax and AgrioUmax. Since the Limaces are 

 already provided with a name, why should we not adopt " Lima- 

 cella " for the other species, namely the Agriolimax, as has been 

 done in scores of similar cases? Still I do not care to advocate the 

 use of " Limacella " for any group, as no definition worthy of accept- 

 ance has been given of it. 



(3) As to the Jjimacella nebulosa (Raf. ?) Ckll., I do not see how 

 it is to be separated from carolinensis as that species is figured by 

 F^russac. The characters given by Mr. Cockerell are Avholly 

 insufficient. Why does he not tell Avhether the jaw is ribbed or 

 smooth ? We would tlien have some clue of value. Measurements 

 taken from variously and generally badly contracted museum spec- 

 imens of slugs are practically of but little use. 



