CORllESPOXDEXCF. 
211 
examination has induced me to believe tliat they were not in the un- 
disturbed brick-earth, but in the lower part of the bed which lies immedi- 
ately upon it, consisting of washed brick-earth, the run of the hill. In this 
bed, which at this particular point is between 7 and 8 feet in thickness and 
deepens towards the 2s .E., there is a great difference between its upper 
and lower portions, for about 4 feet from the upper surface it contains a 
very large quantity of flints, below that they are less frequent, and disap- 
pear as you approach the true brick-earth. At first sight, there seems to 
be but little or no difference between the lower part of the rain-wash bed 
and the true brick-earth. Also, from the men that removed the soil im- 
mediately over the skeletons, I found that there was distinct evidence that 
it had been disturbed, for part of the upper portion of the bed was found 
mingled with the lower ; that and the fact that the stone was between the 
skeletons, close to the skulls, would tend to show that they had been buried 
there, though perhaps at some remote period. 
I remain, j'ours sincerely, 
H. F. IhVEES. 
Sidtiey Villa, Luton, Chatham, May 25, 1863. 
Holoptycliius and Glyptolepis. 
Dear Sik, — Will you allow me space for a few remarks on communi- 
cations which have recently appeared in your pages, and which have been 
suggested at least by articles of mine ? 
And first, as to the restoration of Pteraspis, I intended that in m}' second 
diagram the posterior portion of the test should be marked off by a dotted 
or broken line. I was uncertain as to the exact position of the s])ine, and 
did not therefore venture to restore that portion, although specimens of it 
separated from the test were in my possession. Mr. Powric's beautiful 
specimen clearly indicates the character and position of the spine. But 
on looking at his figure, it will be seen that it confirms the remark which 
I made, and which I considered the chief point brouglit forward by me, 
even that our Scottish specimens do not show any separation between the 
cornua and the test, but that the terminal edge on either side of the spine 
is continuous. I willingly admit that a shade of doubt rests on my first 
diagram ; but I had virtually slated the ground of that myself, and I con- 
sider that diagram as of value chiefly in exhibiting the long-snouted form 
which the shield of Pteraspis sometimes assumes, perhaps indicating spe- 
cific difference. I put forward my third diagram as entirely conjectural, 
and, along with mj' friend Mr. Powrie, must turn to the rocks, in the hope 
of finding some of those long-entombed relics which will throw light on 
the matter. 
And then, as to the case which has been so much debated in your co- 
lumns, — Holoptycliius V. Glyptolepis, — I knew from Mr. Powrie's own 
article in the Quarterly Journal of the Geological Society that Glyptolepis 
liad been noticed in the sandstone of Dura Den, and I simply wished to 
describe a slab in our local museum from that locality. I did not know 
what correspondence there might be privately between those who were 
• interested in the matter. I am glad, however, that the attention of Mr. 
Davies has been called to it, and that he has communicated to your readers 
the results of his keen discrimination. On the specimen of Holoptj/chius 
Aridcrsoni, to which I have access, there are several scales towards the 
posterior part of the body, which display what Mr. Powrie calls so ])ic- 
turesquely " the crescent of points ;" but from what was said in the ' De- 
