GASTEROPODA. BULLADZ. 35 
Bulla haliotoidea, Mont. Test. Brit. 211. t. 7. fig. 6, testa. 
Lamellaria tentaculata, Mont. Trans. Linn. Soc. xi. 186. t. 12. 
figs. 5-6. 
Bulla tentaculata, Turt. Conch. Dict. 25. 
Habitat in Danmoniz estuariis rarior. 
Shell elongate, the spire slightly elevated, transversely stri- 
ated finely, but irregularly. Colour pearly white, without ini- 
descence. 
Animal yellowish, with brighter spots of the same colour. 
Mantle with thin margins. Tentacula elongate. Length of 
the animal an inch ; of the shell three-quarters of an inch. 
Inhabits estuaries on the coasts of Devon and Cornwall ; it 
is found occasionally in the Kingsbridge Estuary, near the 
Saltstone ; and at the mouth of Padstow Harbour. Dr. Goodall 
has found it at Weymouth. 
Although Montagu distinguished the animal of this species 
from that of the following, he nevertheless figured the shell of 
this species for that of M. complanata. 
2. MARSENIA COMPLANATA. 
M. testa ovata depressa, spira deplanata. 
Habitat in Britannie littoribus arenosis, passim. 
Shell ovate depressed, the spire not elevated. Animal yel- 
lowish or rufous-brown, sometimes reddish. Tentacula of a 
moderate length. Length of animal three-quarters of an inch ; 
of the shell rather more than half an inch. Colour of the shell 
similar to that of M. producta, and its sculpture the same. 
Inhabits most of the sandy coasts of Great Britain, and is 
very common. 
As no British conchologists seem to have distinguished dit- 
ferences in the shells of the above species of Marsenia, I con- 
clude that they have never met with both of them in the same 
cabinet ; and as all their figures are very incorrect, | am under 
the painful necessity of refraining from quotation. 
FAMILY IV. BULLADZ. 
Acera, Miiller. 
Bulla, Cuvier. 
