396 Transactions, 



considerable — probably sufficient to form a certain amount of fine sus- 

 pended matter. 



How mucb of the suspended matter in the Hooker River is liberated 

 from the melting neve, or how much originates from the attrition of the 

 fragments that are carried along by the fast-flowing stream, or from 

 ice-erosion of the glacier rocky bed, is indeterminate. At any rate, Dr. 

 Marshall has neglected to take into account some obvious sources of sus- 

 pended matter, other than ice-erosion. For that reason I am unable to 

 regard his tests as a trustworthy basis for the computation of the rate of 

 ice-erosion of the Hooker and Mueller Glaciers. 



Art. XXIX. — On a New Species of Coral from the Lower Oamaruian Tuffs 



near Deborah, Oamaru. 



By Professor James Park, F.G.S., Otago University, Dunedin. 



[Read before the Otago Institute, 5th December, 1916 ; received by Editors, 30th December, 

 1916; issued separately, 30th November, 1917.] 



Plate XXVII. 



Family OCULINIDAE Milne-Edwards and Haime. 



Genus Oculina Lamarck. 



Oculina oamaruensis sp. no v. 



Corallum dendroid, branches cylindrical or subcylindrical, from 1 cm. to 

 3 cm. in thickness ; calices circular ; diameter of calices from 3 mm. to 

 5 mm. ; calices usually from two to three diameters apart, but in a few 

 cases less than one diameter on young branches ; in axial direction calices 

 show a tendency to be disposed in regular spirals. The margins of the 

 calices are slightly raised ; in some cases they may project as much as 

 2 mm. The cavity of the calice is shallow. Only casts were available 

 for examination, and as the material forming the casts is somewhat coarse 

 in texture the septa are not well preserved, and hence cannot be numbered. 

 For the same reason the pali teeth are obscure. The columella appears to 

 be well developed. 



Locality.- — From bed of calcareous tuff overlying pillow-form basaltic 

 lava at old quarry on north bank of Awamoa Creek, half a mile north of 

 Deborah railway-siding. 



Geological Horizon. — The calcareous tuff lies about 45 ft. below the 

 Oamaru stone. It therefore belongs to the Waiarekan stage of the 

 Oamaruian. 



Age. — Probably Lower Miocene or Oligocene. This is the first recorded 

 occurrence of the genus Oculina in New Zealand. The Oamaruian species 

 appears to be almost identical with 0. mississippiensis (Conrad), 1900, from 

 the Vicksburgian Oligocene of the Lower Mississippi. It may be noted 

 that Oculina mississippiensis (Conrad), 1900 = Madrepora mississippiensis 

 Conrad, 1847 ; Oculina americana Milne-Edwards and Haime, 1857 ; and 

 Dendrophyllia mississipjnensis Conrad, 1866. 



