LIMN^US. 173 



on the ventral side ; more gradual and less convex dor- 

 sally. Mouth peculiarly and obliquely prominent, so as 

 to project chiefly below, subpyriform-ovate, carved and 

 acutely peaked above, well rounded below, all but occupy- 

 ing the entire length, yet only filling four-sevenths at most 

 of the ventral area, since the body swelling into the 

 aperture does not so quickly attenuate posteriorly as 

 in most of our Limnai. Outer lip acute, regularly ar- 

 cuated, not sinuated at the edge, receding below. Pillar 

 lip very thin, white, slanting to the right, not at all 

 appressed, but disclosing the umbilical chink. No decided 

 columellar twist. Length seven lines and a half; breadth 

 half an inch. 



The animal is of the usual form in this genus, but is a 

 little broader than that of pereger. It is of a dark olive 

 colour spotted with opake yellow. The cloak is nearly 

 black with a few paler spots. 



It was first detected by Mr. Burnett of Newcastle in 

 the stomach of trout caught in Loch Shene, Dumfries- 

 shire, where it was afterwards taken alive by the same 

 gentleman (Alder). Mr. Jeffreys (who regards it as a 

 variety of pereger) informs us that it has been taken by 

 Mr. M. Moggridge in Llyn y van fach, Breconshire. 



With some hesitation we annex as a variety to this 

 species the Limnceus pereger, var. 4. (lacustris) of Gray's 

 Manual (p. 234, pi. 11, fig. 101 b. — Ampliipeplea lacustris, 

 Brown, II. Conch. G. B. p. 30, pi. 15, f. 24, 25?) figured 

 by us in plate CXXXII. fig. 10. The apex is eroded, 

 not quite sunken, and yet barely elevated above the body 

 whorl ; the pillar is more appressed. It is not improbable 

 that both this and the typical Burnetii may prove in 

 the end to be abnormal forms of pereger. We have 



