Freshivater Mollusca of Ireland. 



205 



Limax carinatus. 

 Limax Sowerbii, Ferus. ? 



LaBergerie; Monivea; county Galway, under stones in fields, and 

 in tufted plants in gardens. There is not any figure in Ferussac to 

 which I could refer the La B. varieties (if they are varieties). Nor 

 does Mr. Gray's description agree well with them ; the word " tes- 

 selated " does not accurately describe the distribution of their co- 

 lours. Their head and tentacles are never " black," but always 

 gray, or blueish-gray. The usual colour is yellowish-brown, often 

 approaching to dusky, sides pale, gray clouded with light yellow, 

 head and tentacles blueish-gray. 



Variety. Deep dusky or nearly black, sides pale gray, head and 

 tentacles blueish-gray. 



The young have the keel yellow-coloured, which in adults is 

 generally the same colour as the back. The extreme dark colour 

 of the variety led me at first to confound it with the L. gagates of 

 Ferus. He remarks of one of the varieties of L. gagates, " Elle est 



d'un gris bluatre ou nouratre plus pale lateralement." I have 



seen but a single individual in Monivea ; it was identical with the 

 variety. 



The internal shells are a size smaller than those of L. agrestis ; 

 they have no membrane on the edge, are opake, much thicker, and 

 not concave ; the peculiar thickening process in the centre gives 

 them the appearance of having a marginal zone, or as if a smaller 

 sized shell were placed on the top and centre of the larger, leaving 

 a rather broad margin, which is usually of a rufous colour towards 

 the top. 



I find that this species is capable of forming a slimy thread in 

 the same manner as L.filans. Having placed one on a laurel, I 

 was surprised by seeing it forthwith make use of this means for 

 conveying itself in safety to the ground. I have since succeeded in 

 making other individuals act in a similar way. The spinning li- 

 maces may be easily forced to do so by leaving them on an ever- 

 green or other tree which may not be congenial to their tastes, when 

 they will speedily effect their escape in this manner. 



[Mr. Clarke has favoured me with living specimens of this Limax, 

 from La Bergerie, and judging from descriptions and figures, I should 

 not hesitate to consider it L. Sowerbii. A species, similarly keeled 

 from the shield to the tail, and of which a very few specimens were 

 obtained near Clifden, Connemara, during a tour made to the west 

 of Ireland, in July 1840, by Mr. R. Ball, Mr. E. Forbes, and my- 

 self, corresponds more nearly with the L. gagates, as described and 

 figured by Draparnaud, than with the British descriptions of L. 

 Sowerbii. They are from half an inch to an inch in length, the 

 head, back and sides blackish, the foot pale gray ; in one individual 

 the dorsal keel was narrowly margined with yellow. They were all 

 found under stones in wet places. — W. T.] 



Note. — On looking over the Appendix to Mr. Gray's edition of 

 Turton, I find he quotes M. Bouchard Chantreux, in observing, 

 that *' the young of Arion ater is dull brown, with yellowish sides." 



