42 



CERATODUS FOSTERI POST-PLIOCENE. 



is employed on its proper work. Meanwhile though the rocks 

 are silent their modern detritus has given some response to the 

 question. Remains of Ceradotus have appeared in the post-pliocene 

 drifts of the Darling Downs, and we now know that the fish 

 inhabited the waters of Queensland before the present systems of 

 its watersheds were established : that is, before changes, whether 

 of surface levels or climate, had laid dry the area now traversed by 

 the Oondamine, and drained the swamps and lakes left fcr a time 

 upon its basin. Protected by its aquatic surroundings from the 

 full force of the new influences to which most of the land animals 

 of the period succumbed, the Ceratodus saw them perish, but 

 its survival was ir. those only of the present waters to which it 

 had access, and which remained suitable to it : it was lost to those 

 now running south, and to those which form the southern head 

 of the Fitzroy; it remained in, or entered those only of the Mary 

 and Burnett. To account for its presence in these rivers, we must 

 suppose one of two things: either while still living in the 

 Oondamine area under the old arrangements of surface, its range 

 was extended to that drained by the rivers mentioned by some of 

 the known or unknown modes of distribution, or there ensued 

 from some geological agency a solution of the continuity of the 

 water area accupied by its then wider habitat. The question must 

 remain open until the geologist has determined the date of the 

 upheaval of the Bunya Range, so called, or of the filling up of its 

 passes by basaltic overflows. The fact originating the question is 

 that the Ceratodus, that is the living one, C. Fosteri, once existed 

 intheCondamine: the proof of this mustnow be offered. Someyears 

 ago a tooth of Ceratodus, obtained from the Darling Downs, was 

 submitted to the late Mr. Krefft. It was apparently so difierent 

 to the teeth of the living species that Mr. Krefi*t regarded it as 

 new and gave it the name of C. Palmeri, but, as I am assured, 

 published no description of it; a notice of it, however, accompanied 

 by a cast, was communicated to Sature^ Feb. 12, 1874, p. 292. 

 During the last year the collectors employed by the Trustees of 

 the Queensland Museum obtained several other examples from 

 the Chinchilla conglomerate in which they are associated with 

 remains of crocodiles, turtles, ^c. These are the specimens 

 before the society and among them is the type of Mr. Krefft's C. 

 Palmeri. It will be remembered that the Mesozoic teeth are in 

 every character extremely variable, and the recent acquisitions fully 

 maintain the family peculiarity, no two are ahke in detail: but just 

 as among the diversities presented by the fossil polymorphus we 

 discern a general resemblance sufficient for their collection in one 



