106 



Var. 11. Succineceformis. Shell shaped like a Succinea, 

 and very thin : whorls 4 : spire small and oblique. 



Var. 12. decollata. Shell more or less eroded : spire 

 truncate. 



Var. 13. sinistrorsa. Shell resembling that of a Physa in 

 having the spire sinistral or reversed, rather solid ; the spiral 

 ridges distinct and prominent. Limnceus lineatus, Bean, 

 MS.; F. & H. iv. p. 168, pi. cxxiii. f. 7. 



Var. 14:. scalariformis. Shell oblong, with deep and 

 regular transverse striae : whorls more or less disjoined : 

 suture consequently very deep. 



HABITAT : Still and slowly running waters every- 

 where. Var. 1. Loch Shene, Dumfriesshire (Burnett) ; 

 Breconshire (Moggridge). Var. 2. Mountain-lakes in 

 Zetland, Scotland, Ireland, and the North of England. 

 Var. 3. South Devon (Montagu); South Wales (J. G. J.) : 

 thrown up by the tide at the mouths of rivers. Var. 4. 

 Lakes, canals, and large ponds ; attaining sometimes a 

 considerable size. Var. 5. With the last. Var. 6. Ponds. 

 Var. 7. Lewes, Suffolk ; Church Stretton, Salop ; Bear- 

 haven, Co. Cork (J. G. J.). Var. 8. Appin, Argyleshire 

 (Bedford). Var. 9. Ulva L, Hebrides (same). Var. 10. 

 Marshes on the sea-coasts of Glamorganshire and North 

 Devon (J. G. J.). Var. 11. Kensal Green (J. G. J.). 

 Var. 12. Church Stretton ; Oxwich, near Swansea 

 (J. G. J.). Var. 13. Scarborough (Bean). Var. 14. 

 Warminster (J. G. J.). This and the two last forms are 

 rather monstrous than varietal. This species is fre- 

 quently met with in our upper tertiary beds. The typical 

 form and several of its varieties extend from Siberia to 

 Sicily. It is a very ubiquitous species ; and Capt. Hut- 

 ton found a variety of it in Afghanistan. 



The variability of this common and abundant species 

 is equal to the extent of its geographical distribution. I 

 was at first inclined to consider that the Limneus ovatus 



