Tertiary Fossils. 2S^ 



Fam. ASTRAEIDAE. 

 Genus Monti ivaltia, Lamaroux. 

 cf. MontUvaltia, sp. 

 A species with a large discoidal, depressed calyx. 

 Cuduiore Collection. 



Genus Orbicella, Dana. 



Orbicella tasmaniejisis, Duncan sp. Plate I. Fig. 1. 



Ileliastraea tasinanlensis, Duncan, 1876, Quart. Jouru. GeoL 

 See. vol. XXXII. p. 342,j pi. XXII., Figs. 1-3. 



Astrangia tahulosa, Tate, 1893, Journ. R. Soc. N. S. Wales, vol. 

 XXVII. p. 145, pi. Xlll. Fig. 2. 



Two species of the above named coral were presented by Dr. 

 Griffith Taylor. They occur in the hard, reddish limestone of the 

 Tertiary series, and were found on the surface of a salt lake east 

 of Ooldea. One of them is preserved in hard, semi-crystalline 

 limestone, in Avhich the coral structure is much obscured; whilst 

 the other is weathered and whitened, so that it has the appearance 

 of a living coral. The structure of the weathered specimen is, how- 

 ever, none the less perfect, for this process has simply picked out 

 the calcareous infilling. A large number of wind-worn pieces of 

 this coral was also secured by Mr. Cudmore. who states that ther 

 occur scattered over the limestone plains. By their blackened and! 

 polished surfaces the fragments appear to have been exposed to 

 the weather for a long time. 



The species, living and fossil, formerly referred to the genus- 

 Ileliatitraea, are now relegated to Orhicella by Verrill and Quelch" 

 by reason of priority. 



There is a close agreement of these specimens from Ooldea with 

 those from Tasmania, though the former have the calices rather 

 larger in diameter (9 :iS). The weathered specimen shows that, 

 although tlie dissepiments are, as a rule, curved downwards, this is 

 by no means invariable. This specimen has the mesenteric pouches 

 filled with a pale glauconite, thus showing, in common with other 

 organic marine bodies, a tendency for the body cavity to act as a 

 receptacle for the deposition of the hydrous silicate of iron, alumina 

 and potash to form that mineral. 



Orhicella tasmaniensis has, up to the present, been unknown 

 from any locality outside Tasmania, excepting Flemington, Victoria. 



Taylor and Cudmore Collections. 



2. Rep. Chall., Vol. XVI., Zool. 1SS6, p. 106. 



