DICKIE, ON DIATOMACEH AND MOLLUSCA. 9 
contained on them have any resemblance to those discovered 
by me on the Northumbrian shore. M. De Brébisson at the 
same time informed me that he had not published any 
description of these new forms. In January last I sent him 
a copy of my paper, and after reading it he wrote to me to 
say that he had adopted all my names for those particular 
species, with which he was previously acquainted ; thus ex- 
onerating me from all blame in the matter. On this ground, 
therefore, Dr. Arnott ought not to express his disapprobation. 
On a Derosit of Diatomacr® and Mouuuvsca, in the County 
of Antrim. By G. Dicxiz, M.D., Professor of Natural 
History, Queen’s College, Belfast. 
In a field at Bellahill, a few miles from Belfast, and in the 
County of Antrim,a sepulchral tumulus has existed from time 
immemorial. 
In the end of January last, this mound was opened, under 
the superintendence of the Rev. A. J. Lee. It seems to have 
had for its foundation the surface of the ground where it 
was reared ; that is to say, there was but little previous exca- 
vation, the ashes of the deceased having been placed on or 
near the surface, and then the earth and other material heaped 
over them. Mr. Grattan, of Belfast, first directed attention 
to the nature of part of the material dug out from the foun- 
dation of the tumulus, having recognised it as one of those 
deposits, called fossil earths, now known to be of very general 
occurrence. 
Two varieties of the earth were found—the deepest in thin 
layers among peat, pure white, and entirely siliceous; the 
other more superficial, in large masses, of a buff colour, and 
effervescing freely with an acid. The presence of calcareous 
matter in the latter was easily accounted for, by the ex- 
istence of fragments and entire shells mixed with it. Two 
of these are common fresh-water mollusca, viz., Lymneus trun- 
catulus and Planorbis vortex ; the former was by far the most 
abundant of the two. Along with them were found four 
well-known land species, Helix arbustorum, H. rotundata, 
Zua lubrica, and Clausilia nigricans ; these were very rare, 
compared with the fresh-water species. 
After careful examination of the deposit, I found the fol- 
lowing Diatomacee : 
VOL. VII. c 
