4 ME. H. B. BEADY ON THE 



how large a proportion of impalpable mud it contained as compared 

 with organic constituents. 



The only satisfactory method of treatment in such cases is to 

 soften the material in water and wash on a fine sieve, proceeding in 

 exactly the same way as with a sample of the recent sea-bottom. 

 Three samples of the Suya deposit have been so examined. In all 

 of them the proportion of residue remaining on a sieve of 120 meshes 

 per linear inch was extremely small, and consisted mainly of 

 Poraminifera with a few Ostracoda. 



I. Light-grey rock from a cutting on the shore-road close to 

 the sea-level. 



II. Similar material, of rather lighter colour, from an elevation 

 of 100 feet or more. 



III. Nearly white, somewhat harder and more compact specimen, 

 from an intermediate point. 



So far as the Microzoa are concerned, the first two present no 

 important differences — none that might not be observed in dredgings 

 from the recent sea-bottom, taken at similar depths a little dis- 

 tance apart. Of Foraminifera they have thirty-six species in 

 common. The whiter sample, ISTo. III., differs from the others in 

 the comparative absence of Lagence and Nodosarinoe ; and appears, 

 from both positive and negative indications, to have been deposited 

 in somewhat deeper water. In aU three there is a remarkable 

 scarcity of arenaceous forms. Subjoined are a few notes on the 

 rarer and more interesting species, together with a complete list 

 of those furnished respectively by the samples above described. 



6. Haplopheagititim etjgostjm, d'Orbigny, sp. (PI. I. fig. 2.) 



" Lenticulae minusculae petrefactae, calcareae nempe aut siliceae," 

 Soldani, 1798, Testaceographia, vol. ii. p. 110, pi. 2Q. fig. N. 



Bobulina rugosa, d'Orbigny, 1826, Ann. Sci. Nat. vol. vii. p. 290. 

 no. 21. 



Lituola rugosa, Parker, Jones, and Brady, 1871, Ann. & Mag. 

 Nat. Hist. ser. 4, vol. viii. p. 242. no. 117, pi. 9. fig. 31. 



The only arenaceous Poraminifera found were two specimens, 

 about -g^y 3]ach (0-4 mm.) in diameter, of Nautiloid contour, depressed 

 at the umbilicus, and with thin rounded margin, but bearing 

 little external evidence of segmentation. The interior of the test 

 appeared, in section, to be constructed very much after the manner 

 of such forms as Eaplophragmmm pseudospirale, Will., sp., that is 

 to say, roughly subdivided by aggregations of sand-grains, but 

 without any regular or definite septa. 



The specimens under notice may, I tbink, be referred to a species 

 founded by d'Orbigny on a figure in Soldani's ' Testaceographia,' 

 loc. cit., from a fossil occurring in the later Tertiary deposits of 

 Coroncina, near Sienna. 



Under the name Haplopliragmium acutidorsatum (Jahrb. d. k.-ung. 

 geol. Anstalt, 1875, vol. iv. p. 10, pi. 1. fig. 1), von Hantken figures 



