308 OCCURRENCE OF DIATOMS, RADIOLARIA AND INFUSORIA, 



is 0-0835 mm., and the width 0007 mm. The diameter of the 

 meshes is about 0*0015 mm. 



This form resembles that figured by Riist in " Palaeonto- 

 graphica," 1885 ( Yol. xxxi., PI. xliv. (xix.), fig. 1) from the Jurassic 

 coprolites of Ilsede in Hanover, and the recent form figured by 

 Saville Kent in his Manual of the Infusoria (1880-1882, Vol. iii., 

 PI. xxxi., figs. 18-19). This form is Tintinnns denticulatus, Ehr. 

 Saville Kent states (op. cit., Vol. ii , p. 607) that this form is salt 

 water in its habit, and that it is found in the Baltic Sea and on 

 the Norwegian coast, and that its distribution would appear to be 

 general and abundant throughout the seas of Northern Europe. 

 Kent, however, describes its lorica as having its "surface regularly 

 shagreened with minute hexagonal facets," whereas in the Queens- 

 land Lower Cretaceous form the lorica consists of open hexagonal 

 meshwork, resembling in this respect the form figured by Riist. 



A great variety of loricae of infusoria are visible in this lime- 

 stone, but for the present we defer figuring them until more of 

 the material is available. 



We beg to gratefully acknowledge the very valuable help that 

 has been given us by Mr. L. C. Green of the Geological Survey 

 of Queensland, who has bestowed much time and care in obtain- 

 ing for us microphotographs of the organisms figured in the plates. 



We also desire to thank Mr. T. Steel, F.L.S., for his kind loan 

 to us of Adolf Schmidt's "Atlas der Diatomaceen-Kunde," and 

 other works relating to Diatoms, and would express our obliga- 

 tions to Mr. J. P. Hill, B.Sc, for his loan to us of his collection 

 of Diatoms, and to Prof. Haswell, F.R.S., for numerous references 

 to works dealino- with the Infusoria. 



EXPLANATION OF PLATES. 



Plate xvii. 



Section showing the Horizon of the Lower Cretaceous Limestone containing 

 Diatoms, Radiolaria and Infusoria, from Maranoa River, Queensland. 

 By W. H. Rands, F.G.S. 



