1 54 Proceedings of tJic Royal Society of Victoria. 



Record in Lower Beds 

 of Muddy Creek. 



Ostriea hyotis, Linn. - - - 7. j). 49 



Placunanomia ione, Gray - - 9. p. 20 

 Pectunculus laticostatus, Q. k G. 10. p. 16 



j' as N. tninida 

 Nucula tenisoni, Pritchai'd - -• 6. p. 224 



I 10. p. 16 

 Limopsis aurita, Brocchi - - 7. p. 50 

 Limopsis belcheri, Ad. li: R. - 7. p. 50 



Saxicava arctica, Linn. - - 2. p. 113 



On the following page of the Correlation Paper (p. 17) Messrs. 

 Tate and Dennant state that the number of species passing up 

 from the eocene of Muddy Creek and of Spi'ing Creek into 

 younger deposits is distinctly opposed to our view of the succes- 

 sion. As in the last instance, however, we must take exception to 

 the figures on which they base their calculations. They state 

 that thirty species from Muddy Creek and sixteen from Spring 

 Creek pass up into the niiocene. Taking the published papers of 

 Messrs. Tate and Dennant as our authorities, and counting the 

 species I'ecorded as miocene, or in a few cases as younger, and 

 "which also occur in the eocene beds, we find our results are 

 widely different from those just quoted. The number of mollusca 

 recorded as passing up from the eocene of Muddy Creek into 

 younger deposits is not thirty but seventy-two, and in the case of 

 Spring Creek, not sixteen but thirty-nine. These records, how- 

 ever, require revision, as although some of the genera have been 

 critically examined since some of the records were made, still the 

 probably incorrect ones have not been expunged, and some 

 species have been recorded with doubt, owing to the imperfect 

 condition of the specimens. In the case of two of the Spring 

 Creek records, namely, Chione prflpitupta and Dosiiiia johtistoni, 

 one of us has elsewhere given reasons for considering them as 

 distinct from the miocene species, and has renamed them. When 

 we reject the species which, after carefully considering the matter, 

 we think should be omitted on the grounds above stated, we 

 obtain for Muddy Creek sixty-eight, and for Spring Creek thirty- 

 three. We are, however, met by a fresh difficulty, and .that is 

 what is the total number of molluscan species hitherto obtained 



