Benson.—Palaeozoic and Mesozoic Seas in Australasia. 21 
are Protospongia, Climacograptus, Dicellograptus, Dicranograptus, Didymo- 
graptus, Diplograptus, Glossograptus, and Retiolites ; while Obolella, Hyolithes, 
Trinucleus, and perhaps Agnostus are present (Hall, 1900, 1902, 1909, 
1920). 
Lower Ordovician rocks form the oldest viderint formations in New 
Zealand, and consist of greywackes, some limestone, graptolitic dee 
appar rently merging into mica-schists. In the ен western extremity 
of New Zealand (Preservation Inlet), originally described by McKay (1896), 
the slates contain Clonograptus, Bryograptus, and Tetragraptus, for which 
reason Hall (1915) correlates them with the lowest агат of the Lance- 
fieldian beds in Victoria and considers them of basal Ordovician age,- 
тенет as pointed out, it is possible they should be classed as uppermost 
Cambrian. The slates seem to pass own into mica-schist and these in 
turn into the so-called “ granitic gneiss,” a sillimanite-paragneiss which 
Park (1921) suggests may represent Cambrian sediments, but in such com- 
plexes the appearance of superposition and relative degree of metamorphism 
cannot safely be taken as proving relative age. In the north-west of the 
South Island of New Zealand the Lower Ordovician rocks are much more 
widespread, though similar in lithological character (Bell, 1907). The 
genera present in the fossiliferous rocks are Bryograptus, Dichograptus, 
Didymograptus, Loganograptus, and Tetragraptus. The determinations made 
by Mrs. Shakespear (1908) and Hall (1915) concur in indicating the presence 
here of two zones belonging to the middle portion of the Lower Ordovician 
Recently Professor Park has discovered a further series of graptolitic slates 
at Cape Providence, twelve miles north-west of the older graptolitic slates 
at Preservation Inlet. is кл determinations of the forms present 
indicate that they are approximately coeval with those last mentioned in 
the northern end of the Island, and with the Castlemainian beds of Victoria. 
(Private communication. 
In regard to the derivation of the Australasian graptolitic fauna, it 
wis be said at once "p the forms present are those of the cosmopolitan 
pelagic types found in Europe, New York, Bolivia, and recently in Peru 
(Lapworth, 1917), dee that in those features in which, according to Hall, 
the Vietorian (and also the New Zealand) zonal succession of forms departs 
from the European succession it accords with that prove Ruedemann 
(1904) to be present in New York. It would appear, therefore, that the 
conditions obtaining in Upper Cambrian times were not wholly reversed 
during the Ordovician peri 
It is difficult yet to trace the sequence of events in the latter part of 
the Ordovician period. A strong folding doubtless occurred, and land 
was subjected to erosion extending throughout the present region of 
Australia, tor where the Silurian rocks are seen in contact with the 
Ordovician rocks in New South Wales—-e.g., the Shoalhaven River as 
described by Woolnough (1909)—there is a marked unconformity between 
them. Indeed, connected with this folding there appears to have been 
a considerable intrusion of granites which have caused profound meta- 
morphism, and according to Browne's observations ( 1914) in the south- 
eastern angle of that State have converted extensive masses of the 
Ordovician slates into mica-schists. The relationship of these to the 
supposed pre-Cambrian schists of eastern Victoria is not yet definite. 
The unconformity between the Ordovician and Silurian slates in central 
Victoria is not so marked. Loftus Hills (1921) has made dins their relation- 
ship in western Tasmania. The basal West Coast Range conglomerate, a 
