46 Dr. Wallich on the Identity of the Chalk 
in the Catalogue as to what he has done with it, I can only 
suppose that it is a species which he omitted to label when 
described, and which has consequently become the type of 
some species in another genus. 
The following group is so close to Azelina that it may save 
the multiplication of synonyms to refer to it here. 
Paragonia deustata. 
Paragonia deustata, Felder, Reise der N ov., Lep. v. pl. exxiv. fig. 8 
(1876). 
Chili. 
Paragonia subornata. 
Macaria ?? subornata, Walker, Cat. Lep. Het. xxvi. p. 1644 (1862). 
Monte Video (Darwin). ‘Type B.M. 
Nearly allied to the preceding species. 
VI.—Supplementary Notes on the EFlints and the Litholo- 
gical Identity of the Chalk and Recent Calcareous Deposits 
in the Ocean. By Surgeon-Major Wauticu, M.D. 
It may be in the recollection of those who have read my 
former observations on the subject * that, in default of any 
Tie available direct means of proving the lithological identity of 
* the chalk and calcareous deposits of the Atlantic and other 
oceans, I was obliged to rely chiefly on collateral evidence in 
support of the view I advocated—namely, that the extraordi- 
nary contrast between the percentages of silica, supposed to 
characterize these two formations, does not in reality exist, 
but is altogether based on the fallacious standard employed 
in making the comparison. I maintained that the nearly 
total absence of disseminated silica now observable in the 
Chalk is not due to an almost infinitesimal quantity of that 
substance having originally been present in it when it rested 
as mud on the Cretaceous sea-bed, but to the fact of nearly 
the whole of the silica it then contained having been then and 
there eliminated from it through the agency of colloidal 
sponge-protoplasm. For a like reason I contended, that the 
large percentage of silica now met with in the surface-mud 
of the recent calcareous areas does not furnish a trustworthy 
index to the percentage which would be found were it possible 
* “¢ A Contribution to the History of the Cretaceous Flints,” Quart. 
Journ. Geol. Soc., Feb. 1880; and “On the Origin and Formation of the 
Ftints of the Upper or White Chalk,” Ann. & Mag. Nat. Hist., Feb. 1881. 
