31 
wise occur. The other shells are ferruginous and include, of 
introduced species, Gryphcea dilatata and JExogyra virgula ; whilst 
Terebratula tama/rinduss and celtica , Pleurotomaria Delahaysii , Pecten 
Pobinaldinus, Ostrea macroptera , and a new species of Sphcera (S. 
Sedgwickii Walk.), seem to belong to the bed and to indicate its age 
as being the period of the Lower Greensand. The bones and teeth 
of fishes, all derived from older formations, represent the following 
genera: — Sphcerodus, Py modus , Gyrodus , Aster acanthus, Leptacan- 
thus, Hybodus , Sphenonchus , Lepidotus , Psammodus , and Pdaphodon. 
The Reptilian remains include bones and teeth of Plesiosaurus , 
Ichthyosaurus , and Pliosaurus ; some teeth belonging apparently to a 
species of Dahosaurus ; and an abundance of water-worn remains of 
Ignanodon , associated with fragments of rock, containing Cyrence , 
indicating that the denudation of Wealden beds has co-operated 
with that of beds belonging to the Oxford and Kimmeridge clays, 
in furnishing the materials for this curious deposit. 
Nov. 6.— The Rev. J. Ken-rick read the following paper “On 
Roman silver coins of the Consular series,” presented by him.—- 
It is called Consular, because it began when Rome was governed 
by Consuls, and ceased when the imperial government was estab¬ 
lished. The unit of the Roman monetary system was a pound 
weight of brass, or rather of bronze, for the as contains a pro¬ 
portion of tin, about seven per cent., with a large mixture of 
lead. Zinc is not found till the imperial times. The name as in 
itself, however, does not denote any specific weight. It is a 
dialectic form for Pis (Gr. oneJ, and is used for unity in other 
connexions, as hoeres ex asse, sole heir. The French as and our 
ace, on dice and cards, are the same word. Originally the As 
was a pound of twelve ounces, but, like our own monetary pound, 
it underwent various reductions, especially in the Punic wars, 
and at the time when the series of silver denarii begins it had 
been reduced to one ounce. The name denarius (tenner) shows 
that it was reckoned at ten asses, and so it is said to have been 
valued in the soldier’s pay, but it was really worth sixteen in 
the reduced scale. I should observe that there is much obscurity 
and inconsistency in the statements of the Latin writers respecting 
the history of their coinage. It is agreed, however, that the first 
silver coinage took place just before the first Punic war; Pliny 
says 485 u. c. or b. c. 269. The Romans had made already con¬ 
siderable progress in that course of conquest, which placed all 
