GASTEROPODA. 249 
Sub-genera. Protw, Defr., P. cathedralis, Pl. IX., Fig. 3, 
aperture truncated below. 
Mesalia, Gray, M. sulcata (var.), Pl. IX., Fig. 2. Greenland 
—South Africa. 
Fossil, Eocene. Britain, France. 
Cacum, Fleming. 
Synonyms, Corniculina, Minster. Brochus, Bronn. Odonti- 
dium, Phil. 
Type, O. trachea, Pl. [X., Fig. 5. Young species, Fig. 6. 
Shell at first discoidal, becoming decollated when adult; 
tubular, cylindrical, arched; aperture round, entire; apex 
closed by a mammillated septum. Operculum horny, many- 
whorled. Lingual teeth, 0; uncini, 2, the inner broad and 
serrulated. 
Distribution, Britain, 11 species, 10 fathoms. Mediterranean. 
fossil, 4 species. Eocene—. Britain, Castelarquato. 
VERMETUS, Adanson. Worm-shell. 
Synonyms, Siphonium, Gray. Serpuloides, Sassi. 
Types, V. lumbricalis, Pl. IX., Fig. 7. 
Shell tubular, attached; sometimes regularly spiral when 
young; always irregular in its adult growth; tube repeatedly 
partitioned off; aperture round; operculum circular, concave 
externally. 
Distribution, 31 species. Portugal, Mediterranean, Africa, 
India. 
Fossil, 12 species. Neocomian—. Britain, France, &c. 
2 Sub-genus. Spiroglyphus, Daud. 8. spirorbis Dillwyn species 
irregularly tubular; attached to other shells, and half buried 
in a furrow which it makes as it grows. Perhaps an annelide ? 
Petaloconchus, sculpturatus, Lea, 1843. 
Miocene, United States, St. Domingo, South Europe. 
Shell with two internal ridges running spirally along the 
columella, becoming obsolete near the apex and aperture. 
SILIQUARIA, Brug. 
Etymology, siliqua, a pod. 
Typo, 8, anguina, Pl. [X., Fig. 8. 
Shell tubular; spiral at first, irregular afterwards; tube with 
a continuous longitudinal slit. 
Distribution, 8 species. Mediterranean, North Australia, 
Found in sponges. 
Fossil, 10 species. Hocene—. France, &c, 
M 3 
