440 G. C. CncJi — Juramc Cephalopoda — Western Australia. 



limestone, attaining the thickness of 30 feet, which occur chiefly in 

 the neighbourhood of Champion Bay, do not seem to be persistent, 

 but are found as it were in patches, which gradually thin out. As 

 the limestone composing them is made up of shells, which in some 

 cases have consolidated into a solid rock, in others have retained 

 their original form, it seems most probable that the accumulation of 

 shells in hollows, in the ancient sea-beds, is the cause of their now 

 being found in isolated areas. The most common fossils found 

 includes species belonging to the [families] Ammonitidce, Belem- 

 nitidcB, Ostreidce, Pectinidm, Trigonidce, Ehi/nchonellidce, etc. These 

 fossils are generally found in the limestone, whole masses of rock 

 being composed of them ; they are also found in the hard ferru- 

 ginous shale and sandstone, in which case they have been converted 

 into oxide of iron. In a paper publislied in the Proceedings of the 

 Geological Society, the author, Mr. C. Moore, considers the fossils 

 from these beds to represent the fossil fauna of the Lias and Lower 

 Oolitic formations of Eng-land. 



" The second principal area of this formation, which embraces the 

 country extending from near Cape Riche to beyond the Phillips 

 Eiver, consists of a series of horizontal sandstones, grits, and con- 

 glomerates, capped generally by the usual ferruginous claystones, 

 the whole thinning out on to the granite along its northern boundary 

 at a level of from 600 to 700 feet above the sea, and forming level 

 plains and table hills, with steep escarpments, along the Gairdner, 

 Fitzgerald, Hamersley, Phillips, and Jerdicart Rivers. To the 

 southward and eastward the formation, which attains a thickness of 

 some thi'ee or four hundred feet, rests on the slaty rocks of the 

 Mount Barren and Jerdicart country. In lithological and strati- 

 graphical character and position, they are almost precisely similar 

 to the same formation in the more northern parts of the colony. 

 "White marly saliferous sandstones, ferruginous grits and claj'stones, 

 conglomerate, reddish sandstones, etc., are the principal rocks met 

 with. Perfect specimens of fossil sponges are frequent in some of 

 the caves which occur along the escarpments, hanging from the 

 roof and sides, where the rock has weathered away ; worn casts 

 are also abundant. Mainbenup, near Esperance Bay, is the farthest 

 point eastward where I have observed the formation. At Cape 

 Riche beds of white and mottled sandstone, overlying granite, form 

 low but steep cliffs along the shore of the bay." 



The present collection of Cephalopoda confirms the view expressed 

 by Clarke ^ and by Moore ^ as to the existence of rocks of Lower 

 Oolite age in Western Australia. Possibly the highly ferruginous 

 rocks may represent a somewhat higher portion of the Oolite, but 

 the evidence of the present collection is by no means conclusive. 

 No species of Middle Liassic age has been recognised in the 

 collection. 



1 Quart. Journ. Geol. Soc. vol. xxiii. (1867), p. 9. 



2 Ibid. vol. xxvi. (1870), p. 230. 



