148 PNEUMONOBRANCHIATA. 



only at the pillar-angle, where there is a minute per- 

 foration. 



32. 14. HELIX fulva. Top-shaped Snail, (t. 5. f. 

 47.) Shell rather conic and trochiform, beneath 

 flattish, with six volutions, dark horn-coloured, 

 smooth, and glossy; aperture narrow crescent- 

 shaped; umbilicus minute. 



Helix fulva. Mutter, Hist. 36. ; Nilson, 13. ; Drap. 

 p. 81. t.7. f. 12; 13. 



Teba fulva. Leach, Moll p. 99. 



Helix trochiformis. Mont. p. 427. 1. 1 1. f. 9. ; Jef- 

 freys, Linn. Trans, xvi. 331., not Ferussac. 



Helix Trochulus. Mutter ? ? Dillwyn, p. 916. ? ? 



nitidula. V. Alien. 



Trochilus. Fleming. 



Var. 1. Mortonii. Shell depressed, both sides 

 nearly equally convex. 



Helix Mortonii. Jeffreys, Linn. Trans, xvi. 332. 



" Trochus terrestris ft. Mortonii Da Costa" Jef- 

 freys, 



Var. 2. Alderi. Smaller, darker. Alder, Mag. Z. fy 

 B. ii. 108. 



Inhab. woods, among leaves and under stones, and 

 on decayed wood. 



Animal grey, shining ; foot thin ; tentacles long. 



Shell the tenth of an inch in diameter, glossy, dark 

 horn-coloured, with six rounded volutions, which are 

 much raised and strongly defined ; the base promi- 

 nent, with a depression in the centre forming an inci- 

 pient umbilicus ; aperture transverse, narrow, as high 

 as broad, with a very thin margin, reflected only near 

 .the depression, which in young shells is hardly visible. 



