COEEESPONDENCE. 
135 
I lately observed the " bone breccia " or " osseous conglomerate " of the 
Upper Keuper Sandstone, which I described some years since in a paper 
read before the Geological Society of London. 
It is exposed in a railway cutting at the village of Eipple, between Upton- 
on- Severn and Tewkesbury, and contains the remains of spines of Lophodiis 
(Acrodus) minimus in great abundance. I also recognized portions of 
Ceratodus cloasinus, of Quenstedt, with scutes and other fragments of the 
bones of Labyrinthodon. It is the richest Keuper-bed I know of in Eng- 
land, and well worthy the attention of all collectors of fossils. Henry Brooks, 
of Ledbury, would be a good guide to the place, and knows the bed which 
is so fossiliferous. I am. Sir, yours obediently, W. S. Symonds. 
Pendock Rectory^ near Tewkeslury, Feb. 26, 1863. 
Soloptycliius V. Gli/ptolepis. 
Sir, — Mr. Powrie, in his communication in the last number of the ' Geo- 
logist,' says : — " The only species of Holoptychius on which I have never 
yet been able to detect scales showing the crescent of points is II. Ander- 
soni." It may interest Mr. Powrie and others also, concerned in the ques- 
tion of Holoptychius r. Glyptolepis, to learn that the typical specimen of 
S. Andei^soni described by Agassiz, and figured in his ' Vieux Gres 
Eouge,' pi. 22, f. 3, now in the British jMuseum collection, has the sculp- 
turing of points, which Mr. Powrie has failed to detect in other examples 
of this species. 
In confirmation of Mr. Powrie's statement that he has detected them 
on scales of all the other species which he has examined, I can state that 
they are present, and well developed, on the posterior scales of the fine 
typical example of H. nohilissimns from Clashbenuie, and also on scales of 
most of the specimens in the national collection, referred to this genus, 
from Dura Den, Nairn, etc. ; and they are discernible on one or two of 
the scales of the fragment of Platygnathus in the same collection. 
So far as my own observation goes, the " crescent of points " is entirely 
absent on the scales of the anterior portion of the body, but becomes 
more and more developed as the scales recede backwardly — dorsal, lateral, 
and ventral — towards the posterior portion. But this particular sculptur- 
ing is by no means a new discovery ; it was observed by the earlier de- 
scribers of the genus ; and among others Hugh Miller, in his * Old Eed 
Sandstone,' describes them as " an inner border of detached tubercles." 
And M'Coy, in his description of H. Andersuni, says that in all cases, the 
anterior part" (of the scale) " is occupied by a patch of rather coarse ra- 
diatingly disposed granules, from whence the ridges arise that go to the 
free edge." He intimates, also, that they are present in his H. Sedgwickli. 
Without offering any opinion as to tlie distinctive generic value of this 
sculpturing, there is one noticeable character, which is mentioned by Mr. 
Mitchell, — the much less degree of imbrication of the scales of Holoptycliius 
compared with those of Glyptolepis ; the scales of the former consequently 
exhibit a greater exposed surface, and are not so numerous as in the latter 
genus. And whilst the scales of Glyptolepis are so very variable in form 
and sculpturing, according to their position on the body, " whence," says 
Professor Huxley, " arises such an amount of unlikeness, that different 
species might readily be founded on scales from different regions," the 
scales of Holoptychius, on the contrary, — with the exception of the pre- 
sence or absence of the lines of points, and minor differences of sculptur- 
