341 



PALEONTOLOGY. 



of cartilaginous fishes. Mr. Broderip observes,* " that it may 

 not be uninteresting to note that a recent species of Trigonia 



has very lately been 

 discovered on the 

 coast of Australia, 

 that land of marsu- 

 pial animals. Our 

 specimen lies im- 

 bedded with a num- 

 ber of fossil shells 

 of that genus." Not 

 only Trigonicc but 

 Terebratidce exist, 

 and the latter ab- 

 undantly, in the 

 Australian seas, 

 yielding food to 

 the Cestracion, as 

 their extinct ana- 

 logues doubtless 

 did to the allied 

 Plagiostomes with 

 crushing teeth, cal- 

 led A crodus, Psam- 

 modus, etc. Arau- 

 carice and cycadeous 

 plants, like those 

 found fossil in ool- 

 itic beds, flourish on 

 the Australian con- 



Fig. 114. 

 After Fitton. 



1. Rubbly limestone (cornbrash). 



2. Clay, with Terebratulites. 



3. Limestone rock. 



4. Blue clay. 



5. Oolitic rock. 



6. Stiff clay. 



7. Oolitic rag, or limestone. 



8. Sanely bed containing the Stonesfield slate. 



tinent, where marsupial quadrupeds now abound ; and thus 

 appear to complete a picture of an ancient condition of 

 the earth's surface, which has been superseded in our hemi- 



* Zoological Journal, vol. iii., p. 408, pi. xl., 1828- 



