PREFACE. 
given any illustrations, but which are intended to facilitate the 
recognition of strata of this age by the field geologists now engaged 
on the eastern extensions of these beds. Some of the species (as 
the Spirigerina reticularis, Leptena depressa or rhomboidalis, 
Spirifera sulcata, &c.) are identical with well-known abundant and 
characteristic forms in beds of the same age in England, Bohemia, 
Sweden, and North America; while others are representatives, 
peculiar to Australia, of other forms, such as Pentamerus, allied 
to P. oblongus, &c., characteristic of the same strata in the old and 
new worlds. 
The next plate illustrates a new spheroidal Tertiary species of 
sponge, with long slender radiating silicious spicules of the European 
recent genus Tethya, and a most remarkable extinct gigantic 
species of Sea-pen, or Graphularia, allied to that of the European 
London clay formation, and also closely allied to the Sea-pen now 
living in Hobson’s Bay (Sarcoptilon), but four times the size of the 
living types. These fossils have been found by the Rey. Mr. Legge 
in abundance in the Miocene Tertiary beds of Waurn Ponds, 
and it is to his enlightened zeal we owe our examples of these 
interesting Zoophytes, some of our figures of which suggest the 
idea that the recently announced discovery of the Mesozoic Cepha- 
lopodous Molluscan genus elemnites in the Tertiary strata of 
South Australia may have really been a different interpretation 
of the same objects. 
The ninth plate continues the illustrations of our numerous 
curious extinct Tertiary species of Cyprea. 
The last plate gives further illustrations of the Graptolites of our 
gold-fields slates ; one, of a new type, contributed by M. Thureau 
from Sandhurst or Bendigo ; and another identical with a species 
found in the similar slates of Canada, having the basal plate, not 
seen before in Australian types, although not very uncommon in 
slates of the same age in North America. 
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