XTl. 
F BE FACE. 
For assistance in their resiDective special groups I have to aclftiowledge my great 
indebtedness to Profs. H. A. Nicholson, M.D., of Aberdeen ; T. Eupert Jones, F.E.S., 
of London ; Ealph Tate, F.L.S., of Adelaide ; Sir F. McCoy, F.E.S., of Melbourne ; 
T. W. Edgeworth David, B.A., Sydney; the late Dr. P. H. Carpenter, F.R.S., of Eton, 
and the late Dr. T. Davidson, F.E.S., of Brighton (Eng.); Messrs. Edgar Smith, of the 
British Museum; Stuart Eidley, late of the same Institution; and John Brazier, 
C.M.Z.S. ; George Sweet, Melbourne ; and T. Whitelegge, of the Australian Museum. 
For general assistance and advice I am equally beholden, to Mr. E. Etheridge, 
F.E.S., and Dr. Henry Woodward, F.E.S., of the British Museum. 
Dr. G. J. Hiude, of Mitcham (Eng.), has most kindly conducted an original 
investigation of the interesting Cretaceous Sponge, Furisiplionia Clarhei, for these 
pages ; and I am thus able to afford a much more detailed account of this species. 
But to none am I more indebted than to Messrs. Eobert Kidston, of Stirling, 
N.B., and E. B. Newton, of the British Museum. The former conducted the exami- 
nation of the Palseozoic and Mesozoic Plants, and drew up a lengthy series of notes, 
which have proved of the greatest assistance. After my departure from London, Mr. 
Newton undertook the task of superintending the drawing of the lithographic plates, 
and general custody of the figured specimens. This, no light duty, has greatly 
contributed to the completion of this undertaking. 
The success of all works on Pah-eontology depends in a great measure on the 
illustrations ; and I was fortunate in securing the careful and well-known artistic skill 
of my friends, Messrs. Charles Berjeau and Percy Highley. Taking into consideration 
the exceptional circumstances under which the plates were drawn, they reflect the 
greatest credit on those gentlemen. Additional plates (Nos. 37 to dl inclusive) have 
been kindly undertaken by Mr. G. H. Barrow, of the Australian Museum. 
Messrs. Eichard Hall and W. H. Brown, the former of, the latter late of, the 
Department of Geology, British Museum, have rendered me very valuable assistance — 
the one in preparing microscopic sections and developing specimens, the other in helping 
to unravel many difficult questions of bibliography. 
Finally, as to the sources of the specimens described. The major portion are, 
of course, the result of the Geological Explorations of my Colleague and his Assistants. 
In addition to this, a valuable collection from the Eockhampton District was contributed 
by the late Mr. James Smith, of Eockhampton-, who was also most kind in affording 
general local information. Mr. C. W. De Vis, Curator of the Queensland Museum, 
forwarded me another large series from the same neighbourhood, and many fine 
Cretaceous fossils from various localities. Besides these the cabinets of the British 
Museum, Australian Museum, and the Mining and Geological Museum, Sydney, have 
been laid under contribution. I am indebted to the Eev. II. H. Winwood, M.A., for 
the loan of the few existing specimens of the late Eev. W. B. Clarke’s Collection, 
described by the late Mr. Charles Moore,* now in the Museum of the Philosophical 
* Quart. Journ. Geol. Soc., 1870, xxvi., pp. 226-201. With the exception of these .specimens, the 
whole of Mr. Clarke’s Collection was burnt in the Garden Palace fire at Sydney in 1882. 
