PHYLLOBRANCHIA. TURBONIDZ. 201 
Helix polita, Pult. Cat. Dorset, 49. t. xix. f.15; Mont. Test. 
Brit. 398; M. §& R. Trans. Linn. Soc. viii. 210. 
Turbo politus, Flem. Edinb. Encycl. vii. 75 ; Dill. Desc. Cat. 
781; Turt. Conch. Dict. 217. 
Strombiformis albus, Da Costa, Brit. Conch. 116. 
Turbo albus, Donov. Brit. Shells, t. elxxvii. 
Habitat in mari Danmoniensi et Cornubiensi. Alt. Z une. 
Shell with thirteen, very white, very shining, smooth, opaque 
whorls. Height seven-eighths of an inch. 
Inhabits the sea on the coasts of Devon and Cornwall. 
2. BALCIS TESTACEA. 
B. testa anfractibus novem, testaceis, angustissimis, glaberrimis, 
nitidis. 
Habitat in mari Danmoniensi Occidentali rarissimé. Mus. 
nost. in Mus. Brit. Alt. = une. 
Shell with nine testaceous, very narrow, very smooth, shi- 
ning whorls. Height five-eighths of an inch. 
Inhabits the western coasts of Devon, but is extremely rare : 
it was discovered by Mr. J. Cranch in the Plymouth Sound in 
deep water by an oyster-dredge ; he found five living specimens 
in one day, but although he afterwards tried near the same 
place he could never find any more of them. 
3. BALCIS ARCUATA. 
B. testa arcuata ; anfractibus duodecim, ferrugineis, nitidissimis, 
opacis, glaberrimis. 
Habitat in mari Cornubiensi et Danmoniensi Australi. Mus. 
Montagu et nost. in Mus. Brit. Alt. 2 une. 
Shell curved, with twelve ferruginous, very shining, very 
smooth, opaque whorls. Height two-eighths of an inch. 
Inhabits the southern coasts of Devon and Cornwall. 
This species is equally common with B. /evis, and was sup- 
posed by Montague to be the young of that species. 
