98 
Geology and Physical Geography ; 
• Near Amherst is a deposit (probably lacustrine) of infusorial 
earth, seventeen feet in thickness, resting on basalt. It is com- 
posed entirely oi the siliceous skeletons of microscopic animal- 
culre (Diatomaccce) and is largely used in the manufacture of 
dynamite. Further remarks on the Pliocene gravels will bo found 
in connexion with the subject of auriferous alluvial deposits in 
a subsequent chapter. 
Among plant remains found in Upper Tertiary deposits are: — 
Eucalyptus Plnli (McCoy), and the various species of fossil fruit 
figured and described by Baron von Mueller, namely Spo ndy- 
lostrob us S mythii, Thymatocaryon Machayi, Trematocuryon 
McLellam, Rhytidotheca Lynchii , Plesiocapparis prison , Cely- 
phina McCoyi , Odontocaryon Macgregorii, Conchotheca rotun- 
da ta, Rhytidotheca plcioclinis , Penteune Clarhci , Pentcuue 
bmchyclinis , Penteune trachyclinis , Dieune pluriovnlata , Platy- 
coila Sullivani , Phymatocaryon angu/are, Conchotheca turgida. 
The principal marine Pliocene fossils figured and described 
by Professor McCoy are: — Mollusea. — 7 'rigonia acuticostata 
(McCoy), ilaliotis Ncevosoides (McCoy), Cerithium Fleming - 
tonensis (McCoy), fValdheimia macropora (McCoy), Ditrupa 
Wormbetensis (McCoy), Lcpralia Stawcllensis (McCoy), Micula 
Mart/us (McCoy), Tellina Krausei (McCoy). Mammalia. — Arcto- 
cephalus William si (McCoy), and Physetodon Bayleyi (McCoy). 
Among laud animals of Upper Tertiary and Post Tertiary times 
are Diprotodon longiceps (McCoy), D. Australis (Owen), 
Phasco/omys pliocenus (McCoy), Thylacoleo carnifex (Owen/, 
Macropus Titan (Owen), Procoptodon Goliah (Owen)’ 
Nototherium Sarcophilus ursinus (Harris), Dasyurus off inis 
(McCoy), Hypsiprymnus trisulcatus (McCoy), Canis dingo ’ and 
others. Somo of these appear to have become extinct at com- 
paratively very recent periods, while one, the Canis dingo, or 
native dog, is still in existence. 
Newer Volcanic. 
The basalts, or anamesite and dolerito lavas, familiarly known 
as “ bluestone,” occur in sheets or strips of varying breadth over- 
lying a large extent of the central western portiou of Victoria. 
The great plains of the western district, from Geelong to Hamil- 
ton and from Colac to Ararat, are uearly wholly of volcanic origin, 
while most of the ancient river-beds or leads trending north and 
south from the Main Divide are more or less filled in and covered 
by lava flows which, though often confined between elevated 
Silurian ridges near the hilly country, spread out and unite with 
the wide sheets that constitute the plains. To the northward of 
Ballarat, portiou of the Main Divide itself is of volcanic forma- 
tion, and a wide sheet extending to the north, and finally disap- 
pearing under the Post Tertiary deposits of the Loddon, covers tho 
