73% 
PENTAMERUS. 
Gen. Cuar. An equal-sided inequivalyed bivalve, 
one valve divided by a longitudinal internal 
septum into two parts, the other by two septa 
into three parts or valves. Beaks incurved, 
imperforate. 
PENTAMERUS Knightii. 
TAB. XXVIIL—Upper Figure. 
Spec. Cuar. Circular, with many longitudinal 
furrows; tripartite valve much depressed, with 
a short slightly-incurved beak ; bipartite valve 
conical, gradually produced into a leng in- 
curved beak. 
ne re BT ara a 
Tue septa in the flat valve extend to its edge, they are 
near each other\and parallel. The septum in the other 
valye divides the beak; the divisions extending to the edge 
of the shell, form a kind of double beak, much resembling 
the horny part of the toes of a pig’s foot, and leave an 
angular hollow within the curve; the stone that fills this 
hollow commonly separates easily, and may at first sight be 
taken for a third valve of a triangular carinated form. 
The edge of the deep valve appears to extend over that 
of the flatter one: the length of the curve from the apex 
to the edge is often six inches. 
About half a mile up the river Teme, near Downton 
castle, the dell is bounded by two steep rocks approaching 
973 YI. 
