Lower Cretaceous Fossils from the Sources of the Barcoo, Ward And
LOWER CRETACEOUS FOSSILS FROM THE SOURCE8 OF THE BARCOO, WARD AND NIV E RIVERS SOUTH OENTRAL QUEENSLA~D. PART II.l-CEPHALOPODA. By R. ETHERIDGE, JUNR., Curator. (Plates xxx.-xlix., and Fig. 8.) I.-IN'l'RODUC'l'ION. The" Ammonites" proper contained in Mr. H. \V. Blomfield's collection are few in nnmber', and will be noticed in a later part of this Memoir. The following descriptions of the "Crioceri" are offered with a considerable amsmnt of diffidence, and to arrive at these results I found it impemtive to undertake a general review of our Cretaceous forms hitherto associated with the names CTioceras and Ancylocera8; the outcome of this work, extending over many months, is t~ my mind, I regret to say, anything but satisfactory. This arises from two primary causes, the frag mentary state in which the fossils are frequently found, and the difficulty experienced in grouping ~uch portions, from many and "widely separated localities, in well dlefined species. A secondary cause is due to the fact that many of the hitherto described forms are based on portions of shells only, and in two instances at least the descriptions are so inadequate that recognition of the species is practically reduced to gue~s work. In no instance is this more apparent than in that of Cl·iocemB australe, Moore, the Australian type of the group. To render my investigations as complete as possible, I assembled all the specimens of the above two genera within my reach, and drew upon the following collections, as well as onr own :-The Mining and Geological, and Macleay Museums, ~ydney; National Museum, Melbourne; Geological Survey, and Queensland Museums, Brisbane; Geological Survey Collection, Adelaide; and the Sweet Collection, Melbourne.
[Show full text]