55 



debris were obtained in a well-sinking near Lake Hurd, nortb of 

 Billeroo trig, in tbe basin of Lake Frome ; they occurred in a 

 stratum of sharp white sand underlying a clay which is re- 

 ported to me to have embedded in it stems of " mulga" (sic). 

 At Kalamurina Station, near Cowarie, on the Warburton river, 

 about 50 miles north from the first-named locality, and in the 

 same physiographic region, there has been exhumed the fore 

 part of the skull of a crocodile, differing from C. porosus, in- 

 habiting tropical Australia, by its shorter, broader, and more 

 massive snout. The specimen graces the Museum at Port Ade- 

 laide. 



In this connection may be reported the discovery of the lower 

 jaw of Macrofus Titan and mandibular teeth of Ceratodus 

 Forsteri in the bed o£ a dry lake near Momba Station, about 25 

 miles north of Wilcannia. The fossils were gathered by Mr. 

 "W. Hogarth, and presented by him to Mr. Gavin Scoular, who 

 has obligingly submitted them to me for determination. The 

 former gentleman writes to the latter that the lake is, accord- 

 ing to the statement of the Astronomer Royal of Sydney, 35(> 

 feet above sea level, and that at times of high floods is filled by 

 the waters of the Darling river, but has not been so until the 

 one of this year since 1864 ; that after the flood of 1864 cod 

 and other fish were caught in the lake. The highly mineralised 

 condition of the organic remains above referred to is suggestive 

 of their having been washed out of a red loam or earth, and 

 precludes the probability of their recent origin. 



As I have elsewhere* pointed out, the existence of the 

 gigantic herbivores in the "dry zone" demands climatic condi- 

 tions favourable to the growth of a vegetation capable of sup- 

 porting them, and that their extinction is attributable to 

 those climatic changes which brought about dessication, invol- 

 ving a reduction in volume of the waters of the lakes, and 

 finally converting their basins into saltpans. 



I need hardly urge that the replacement of the arid plains 

 by freshwater seas, though a consequence of an amelioration 

 of climate, must have had a reciprocal effect, conversely as the 

 existence of a dry zone produces aridity and thereby intensifies 

 the effect. 



Specific Ceiticisms on Me. Scotjlae's Papee. 

 The Ice-marTcs at Blach Foint are on sheared surfaces across 

 the bedding, and their direction is nearly parallel with the 

 trend of the coast. But the consideration of the direction of 

 the marks is of little moment, as we cannot restore the outline 

 of the country at the period of their production for reasons 

 hereafter to be stated. 



* Trans. Eoy. Soc. S. Aust., vol. H., p. Ixvii., 1879 ; vol. VIL, p. 32, 1884. 



