33 



from Baron F. von Mueller and Dr. R. Schomburgk ;' Journ. Lin. Soc, 

 vol. 13, pp. 155, et seq., 1872. The number catalogued is 235, of which 

 43 are South Australian. 



Marine Algce. — Figures of many Australian seaweeds are given in 

 Harvey's " Nereis Australis," and in Hooker's " Flora of New Zealand' 

 and "Flora of Tasmania ;" but in (f) Harvey's " Phycologia Australica," 

 vols. 5, 8vo, 1858-1863, we have a more comprehensive history of this 

 class of Australian plants. In this work the more characteristic sea-weeds 

 are illustrated by coloured drawings, accompanied when necessary with 

 such magnified dissections as will enable any one possessed of a micro- 

 scope to refer with certainty the figure to the plant which it represents. 

 The number of plates is limited to 300, but at least one species of every 

 genus is figured. The species which are figured in earlier works are not 

 repeated in the Phycologia Australica, except in the case of types of 

 forms which could not be omitted without injury to the scope of that 

 work. A synopsis of all known Australian algse is given ; and the 

 number of actually known species dispersed along the Australian coasts 

 is 799 ; of these we appear to have 138 on our shores. The work lacks 

 method in the arrangement of the descriptions, and the omission of a 

 conspectus of the genera is a serious defect. 



GEOLOGY. 



The general geology of South Australia is represented on a (f) " First 

 Sketch of a Geological Map of Australia," by R. Brough Smyth, 1875, 

 which embodies the labours of Selwyn and Woods and the inedited 

 observations of our Survey Department and of some explorers. The 

 country south of Lake Eyre is shown to be occupied by Silurian, 

 Tertiary, and Igneous rocks. Though the broad features seem to be 

 pretty correctly pourtrayed (for as the scale is only 110 miles to an inch 

 no accurate definition can be expected), yet extensive patches of tertiary 

 rocks are known to exist where Silurian is shown, and in the Western 

 District protrusions of the latter are omitted. Moreover, no distinction 

 is drawn between our older and newer tertiaries, which are so widely 

 separated from each other in point of time ; and also the two uncon- 

 formable sets of the Palaeozoic rocks, which were described by Selwyn, 

 are not separately coloured. 



The salient points of our geology about which we want to have 

 accurate information are : — The metamorphic or igneous character of the 

 granites ; the order of succession of the fundamental rocks ; the age of 



