i./ 



224 



beds, which, as yet, are free from doubt as regards their 

 identification with living species. The two exceptions are 

 Limopsis Belcheri (Adams and Eeeve) and L. aurita (Brocchi). 

 But these two, certainly, do not represent one per cent, of 

 the species determined to be extinct, and, consequently, if 

 we are not prepared to reject the per-centage method in the 

 determination of the great divisions of the tertiary period, we 

 must assuredly refer the Table Cape beds not to the miocene 

 but to the eocene, or " early dawn," of the tertiary period in 

 Australia. It is now five years ago (pp. 86-87, Proc. Eoy. 

 Soc. of Tas.) since I made use of the following statement 

 before the members of this Society : — " This continual 

 lessening of the per-centage of living to extinct forms as our 

 knowledge increases is most significant. According to the 

 principle which has been adopted by Mr. Lyell, and through 

 him by nearly all English geologists, this low per-centage of 

 living representatives indicate rather more an eocene than a 

 miocene age for our marine beds at Table Cape." The inves- 

 tigations carried on by Professor Tate and other indefatigable 

 workers, since that time, have placed this matter beyond all 

 reasonable doubt, and now there is every reason to believe 

 that the Table Cape beds, with their Australian equivalents, 

 mark the earliest dawn of the eocene period in Australia. 

 In conclusion, I may venture to prophecy, notwithstanding 

 the gap between the cretaceous rocks of Maryborough, 

 Queensland, and the eocene beds of Table Cape, that the day 

 is not far distant when passage beds will be discovered con- 

 necting these systems more closely together, if not completely 

 merging the one insensibly into the other. 



DISCOVERY OF ENTOMOSTEACA IN THE UPPER 

 MEMBERS OF THE TRAVERTIN BEDS, GEILSTON, 

 AND A DESCRIPTION OF A NEW SPECIES OF 

 CYPRIS. 



By Robt. M. Johnston, F.L.S., Etc. 



[Bead June 9, 1884.] 

 Cypris Alburyana (n. s.). 

 Carapace oblong-oval, somewhat flattened on one side ; 

 valves convex, smooth, shining, white ; breadth contained in 

 length two -and-a-half times ; length usually fmil. Gregarious 

 in the altered opalescent rock overlying the basalt in the 

 Travertin Limestone Quarry at G-eilston. 



