CORRESPONDENCE. 



135 



I lately observed the "bone breccia " or " osseous conglomerate " of 1 lie 

 Upper Keupcr Sandstone, which I described some years since in a paper 

 read before the Geological Society of London. 



It is exposed in a railway cut I ing at the village of Pipple, between Upton- 

 on-Severn and Tewkesbury, and contains the remains of spines of Lophodus 

 (Acrodus) minimus in great abundance. I also recognized portions of 

 Ceratodus cloasinus, of Quenstcdt, 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 Teivlcesburi/, Feb. 26, 1863. 



Holoptychius v. Glyptolepis. 



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 v. Glyptolepis, to learn that the typical specimen of 

 H. Andersoni described by Agassiz, and figured in his ' Vieux Gres 

 Rouge,' pi. 22, f. 3, now in the British Museum 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 arc present, and well developed, on the posterior scales of the fine 

 typical example of II t/obiliss/n/us from Clashbennie, 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 (he earlier de- 

 BCribers of the genus; and among others Hugh Miller, in his ■ Old Red 

 Sandstone,' describes them as " an inner border of detached tubercles." 

 And M'Coy, in his description of II. Andersoni, says thai 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 77". Sedgwichii. 



Without offering any opinion as to the distinctive generic value of this 

 sculpturing, there is one noticeable character, which is mentioned by Mr. 

 ]\I itehell, — the much less degree of imbrication of the scales of 1 1 < »lopt vcbius 

 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," sa\ s 

 Professor Huxley, " arises such an amount of unlikeness, that dillerent 

 species might readily be founded on scales from dillerent regions," the 

 scales of Holoptychius, on the contrary. — with the exception of the pre- 

 sence or absence of the lines of points, and minor dillerences of sculptur- 



