Rev.M.J. Berkeley on Assiminia& Polutadenticulata. 427 
by Cuvier, being one of the rare instances in which a calcareous tube 
occurs in that genus. 
For the other, Serpu/a Filograna, I beg leave to propose a new genus 
which will be characterised by the nature of its opercula and number of 
branchiz, and may be called Filograna ; in which case, Turton’s specific 
name implexa will be very appropriate. 
FILOGRANA, nob. 
Shell very slender, filiform, gregarious. 
Branchie 8, filiform, of which two bear an infundibuliform obliquely 
truncate operculum. 
Mantle rectangular. 
Fascicles of bristles 7 on each side. 
Reference to the Figures. 
PLATE XIX. GOR eT 
Fig. 2.  Ditrupa subulata. mT vein hho 
a. The animal. 
b. One of the branchie. 
e. A portion of the anterior part of the mantle. 
d. Operculum, 
Arr, LVII[. Description of the Animals of Voluta denti- 
culata, Mont. and Assiminia Grayana, Leach. By 
the Rev. M. J. Burkecey, A. M. 
Voluta denticulata, Mont. (Carychium Myosotis, Michaud, Compl. de ' 
’Histoire de Draparn.) and Assiminia Grayana, Leach, abound under 
stones in the salt marshes by the Thames at Gravesend. Having an 
opportunity of examining both in a living state in the summer of 1832, 
