POT AMIDES ? margaritaceus. 
TAB. CCCXXXI X.—Fig. 4. 
Spec. Ciiar. Conical, turretcd ; live close rows of 
bead-like granules surround each whorl, the first 
and fourth row minute, and the fifth larger than the 
other two ; lip expanded, plicated ; columella re- 
curved, obtusely carinated. 
Syn. Murex margaritaceus. Brocehi 447, t. 9./. 4. 
The granulated surface has a very rough aspect; the 
spire is rather shorter in proportion than many of the 
genus ; the largest row of granules is placed near the 
upper edge of each whorl, but is not sufficiently distinct 
to merit the title of a corona ; the lip is thickened and a 
little expanded, it has two or three furrows within its 
upper part, and resembles much that of the recent 
P. muricatus. 
Brought from the upper marine formation of the Isle 
of Wight by Professor Sedgwick. It is unquestionably 
the shell described by Brocchi. 
POTAM1DES? cinctus. 
TAB. CCCXL. — Fig. 1. 
Spec. Char. Subulato-conical, with three rows of 
nearly equal granules upon each whorl, and two 
carinae near the edge of the base ; suture subcana- 
liculated ; columella with one plait. 
Syn. Cerithium einctum. Lamarck Env. de Paris 84. 
A. longer shell than the last, and not so rigid in its 
aspect ; it has a ilatish base, and a thin but enlarged 
