JOURNAL OF CONCHOLOGY. 



NOTES ON THE LIMN^ID^. 

 Limnsea peregra var. Burnetti (Alder). 



By WILLIAM NELSON. 



Limnsea Burnetti (Alder) Ann. and Mag. Nat. Hist., 1848. 

 Limnjeus Burnetti, Forbes and Hanley, Brit. Moll., vol. iv., 1854. 

 Limnsea peregra var. Burnetti (Jeffreys) Brit. Con., vol. i., 1862. 



Shell large, ovate, globular, rather solid ; dull, of a dark 

 horn colour ; finely and rather deeply striate in the lines of 

 growth ; whorls 5-6 ; apex intorted ; the two apical whorls are 

 quite sunk below the third one, after which they begin to fall 

 away from the plane of convolution, giving to the shell an 

 appearance of a spire ; the body whorl is very large and 

 rounded ; the inner lip is reflected on the columella, which is 

 not much twisted, and forms a subumbilicus ; the suture is 

 moderately deep. Length 19 mill., breadth 18 mill. 



This shell was first described as a species by Mr. J. Alder 

 in the 'Annals and Magazine of Natural History' in 184S. It 

 was discovered by Mr. Burnett in the stomach of trout caught 

 in Loch Skene, Dumfriesshire ; afterwards living specimens 

 were obtained from that wild, secluded, and lonely locahty, 

 from which this most able of British conchologists drew his 

 diagnosis. The young shell has somewhat the appearance of 

 LimncBa invohita^ but is darker in colour, more solid and 

 globular. The mature shells are usually much eroded, and has, 

 as Mr. Alder happily describes it, somewhat the appearance of 

 a Nerita. 



The only additional locality that has been recorded is 

 Llyn-y-van-fach, Carmarthen, Wales. I have, through the kind- 

 ness of Mr. J. W. Taylor, had an opportunity of examining 

 specimens from the Welsh locality, and, though I think they may 

 perhaps be referred to this variety, they are by no means so 

 characteristic, and would, I think, point to a shorter period of 

 isolation than those from the original locality. 



J.C, v., April, 1887 



