114 MOLLUSOA FROM THE CRAG. 



rugose, with three longitudinal ridges, the centre one the largest ; the extremity 

 produced, straightened, drawn out, and free ; aperture subcircular. 



Diameter of tube, 5 a line. 



Locality. Cor. Crag, Ramsholt and Sutton. 



Red Crag, Sutton, Bromswell, and Brightwell. 



Fragments of this shell are abundant in many localities. One agglomerated mass 

 in my cabinet is almost as large as a hen's egg; but the specimen figured by Dale, 

 which I imagine to be a group of these tubes, is more than five inches in length, 

 and three and a quarter in thickness. It much resembles V. subcancellatus, Phil. 

 (En. Moll. Sic), but is not regularly cancellated on the exterior. The tube is 

 ornamented by three lines, in a longitudinal direction, the centre one of which is 

 the most prominent, and forms the base or keel of the volution, so that only two 

 are visible where the shell is regularly spiral, and one upon the base below. The 

 shell, when perfect, is covered with rugae or wrinkles in a transverse direction ; but 

 the terminal portion is smooth, and free. In large masses the volutions are irregular 

 and inconspicuous, though the young shell may frequently be traced by its regu- 

 larly spiral form. V. subcancellatus is called by M. Philippi solitary ; the Crag 

 specimens are generally gregarious. This may, however, be only a variety of that 

 species, as he has suggested. 



Fig. 8 a is a specimen attached to an oyster from the Coralline Crag; fig. 8 b 

 is a glomerated mass of these shells, from the Red Crag at Bromswell . 



2. Vermetus Bognoeiensis (?) J". Sow. Tab. XII, fig. 9. 



Vermetus Bognoriensis. J. Sow. Min. Conch, t. 596, fig. 1-3. 



Specimens, of what appears to belong to this species, are occasionally found in 

 the Red Crag. The inner volutions are destroyed in a similar manner to those 

 from Bognor, and the interior of the tube is filled with clay. They are probably 

 washed in from the London clay, and may, perhaps, be the remains of an Annelid. 



Caecum,* Mem. 1817. 



Dentalium (spec.) Mont. 

 Cecalitjm. Flem. 1822. 

 Brochus. Brown, 1827. 



CORNXJOIDES. - 



Odontina. Zborzewsky, 1834, (ex Phil.) 

 Odontidium. Philippi, 1836. 

 Dentaltopsis. Clark, MS. 1847. 



Gen. Char. Shell small, tubular, generally thick and strong ; smooth or annu- 

 lated ; subcylindrical and arcuated ; open at the anterior extremity, with the 

 margin rounded, sometimes thickened ; closed posteriorly with a rounded or mam- 

 millated clausum ; operculum corneous and spiral. 



* Etym. Ccbcus, blind, or closed ; taken from caecum, a term used in anatomy. 



