GASTEROPODA. 
[FAMILY VERMETID. | 
The shells of species of this family are distinguished from 
those of the Serpulcee by the presence of a spiral nucleus and of 
concave smooth interior septa. 
If the shell is formed of a solid matter strongly sculptured 
with longitudinal grooves or scales, or of a brownish colour, it 
is certainly formed by a Vermetus; but if the shell is of a soft 
earthy matter, feebly longitudinally grooved, it is doubtful to 
which it belongs. 
The shells of the Serpulide have an anal opening (except 
Cymospira), and appear only to be composed of two layers, the 
Vermetide having three. 
The interior of several species contains very long lamella, 
generally regarded of generic value; but they are dissolved 
with age, like the teeth of some species of Pupa. 
All the Vermeti are viviparous, and the lamelle within the 
tiibes may serve for the retention of the fry. 
The genera and sub-genera contained in this family are VER- 
METUS (Petaloconchus, Serpulorbis) (p. 249), and SILIQUARIA 
(p. 249). 
[FAMILY CacIDZ&. ] 
Shell with a spiral nucleus; tubular, regular, sometimes 
fixed aperture orbicular ; operculum horny, multispiral; margin 
sometimes fimbriated. 
Czacum, Fleming.* 
Nuclear whorls orbicular, in the same plane as the adult, fre- 
quently decollated; operculum concave or flattened. 
Sections :—Hlephantulum. Comparatively of large size, tapering; 
sculpture longitudinal. 
Distribution, 9 species. Mazatlan (6), West Indies, Mauritius. 
Fossil, 1 species (C. liratum), Carpenter. Cor. Crag. Smntton. 
Anellum (typical Czeca). Adult shell annulated. 
Distribution, 14 species. Europe, Matzatlan, Australia, Japan. 
Fossil, 2 species. Eocene. Paris, Suffolk. 
Fartulum. Smooth, cylindrical. 
Distribution, 10 species. Mazatlan, Teneriffe, Singapore, 
Australia. 
Fossil, C. mamiillatum, 8. Wood. Cor. Crag. Sutton. 
Sub-genera :—BROOHINA, Gray. 
Type, Dentalium glabrum, Mont. 
* See p. 249 : 
oO 26 
