41 
n-HlSTORY OF THE GENUS EURVDESMA. 
1838 . — To Sir Thomas L. Mitchell, Surveyor- General of New South 
Wales, we owe our introduction to this remarkable genus. Mitchell’s first 
journey of exploration in Eastern Australia was made in 1831-2, “ in search 
of the Eiver Kundur.” On arrival at a hill, now known as Harper’s Hill, 
near Allaudale, nine miles from Maitland, in the Hunter Eiver Valley, 
“ a volcanic grit of greenish-grey colour ” was found, containing fossil shells.^ 
These fossils were later examined by Mr. J. de Carle Sowerby. Amongst 
them a shell “near to Isocardia, hut Mr. S. would not venture to say that 
it was of that genus.”" This constitutes the first record of Bury'desma . 
1845 . — The fossils collected by Count Paul E.de Strzelecki, C.B., during 
his explorations in South-east New South M^ales and Tasmania were described 
by Professor John Morris. Strzelecki visited and collected at Harper’s Hill, 
although his published list contains no reference to Eurydesma,^ hut he records 
it from Hlawarra ; in fact, as subsequent observers have not collected the genus 
from the southern coal-fields, it is just possible there was some mixing of 
specimens from the two localities. The peculiarities of Sowerhy’s “ Isocardia ” 
at once struck Morris, who proposed the genus Eurydesma for its reception,^ 
remarking that it “ ought to be arranged very near to Avicida." 
1847 . — During the years 1838-42 the exploration of the Pacific by 
the United States Exploring Expedition under Commodore Wilkes was 
carried out. Professor J. D. Dana accompanied the expedition as geologist. 
New South Wales was visited, and extensive collections were made from the 
Permo-Carboniferous of Harper’s Hill and the Northern Hlawarra District — 
Wollongong and Gerringong (Black Head). Two species of Eurydesma were 
obtained at Harper’s Hill — E. eUiptica, Dana, and E. ylobosa, Dana." 
' Mitchell — Three Exped. Int. E. Austr., 18.38, I, p. 14. 
* Mitchell — Op. cit., p. 15, PI. II, figs. 1, 2. 
’ Strzelecki — Phjs. Descr. N. S. Wales, &c., 1845, p. 89. 
* Morris in Strzelecki — Oju. cit., p. 275. 
5 Dana — Am. Journ. Sci., 1847, IV (2), p. 158. 
