Lias. Oolite. Cretaceous. Tertiary. Living. 



All other Countries 

 except Australia 

 Australia 

 New Zealand 



Say 200 Sp. 



2 



It will be noted from this table that the genus was excessively rich 

 in representatives from its advent at the beginning to the close of the 

 Secondary Age in Europe, when it died out altogether ; whereas in Aus- 

 tralia it has survived throughout the whole period of secondary and 

 tertiary periods until the present day, though it must be admitted in a 

 very limited degree in regard to number. I will now add a list of all 

 known Australian Trigonias : — 



1. 



T. Moorei 



•if 



"Jurassic 



Western Australia. 



2. 



T. lineata 



g^Do. 



Queensland. 



3. 



T. nasuta 



^ [.Cretaceous 



Queensland. 



4. 



T. semiundulata 



6 fMiocene 



'1 1 



o -^ Up. Miocene 



Victoria ; South Australia 



Tasmania. 

 New Zealand. 



5. 



T. Howittii 



1L - 



Victoria. 



6. 



T. acuticostata 



.a 



o 



K5 



o 

 "5 



'Miocene 

 Pliocene 

 Living 



Victoria ; South Australia 



Victoria. 



South-Eastern Australia. 



7. 



T. pectinata 



1 



Up. Miocene 

 ^Living 



New Zealand 

 New South Wales. 



8. 



9. 



In. 

 11. 



T. margaritacea 



T. nobilis 

 T. Strangei 

 T. uniophora 



■fie 



i-i 



'Do. 



Living 

 Do. 



Tasmania ; South Aus- 

 tralia. 



New South Wales. 

 Tropical N. and N.E, 

 Australia. 



In conclusion, I would remark that independently of the scientific 

 interest attaching to the shells I have been speaking of, the casual observer 

 when he sees them must be involuntarily impressed with their beauties 

 and peculiarities. When first discovered at the beginning of the present 

 century in the seas of New Holland they were considered such a rarity 

 by collectors that large prices were given even for old and worn single 

 valves, no better than some of those shown by me. At the present day 



