GEOLOGY AND MINJEEALOttT. 21' 



derived from the denudation of the chalk beds of the neighbouring cretaceous 

 districts. They appear to have attracted more than ordinary attention, various 

 notices of them having been published by Mr. Stowe of Buckingham, (to whom the 

 Institute is indebted for the specimens forwarded through Dr. Gibb,) the 

 Reverend S. G. Osborne, and others; but concretionary bodies of a more or les3 

 similar nature, are well known to be of common occurrence, and frequently to 

 present imitative forms of :i very varied character.* As pointed out on their first ' 

 discovery, by the Reverend Professor Sedgwick, the term " fossil vegetable re- 

 mains," applied to these concretions, is altogether a misnomer; although the 

 original perishable nuclei, around which the calcareous deposition took place — 

 supposing a nucleus to have been present at all — may very possibly, though not 

 necessarily, have been fucoidal. We quote the following passage from Dr. 

 Gibb's communication, forwarded with the specimens in question: — "The 

 presence of fossil infusoria seen in these specimens, does not necessarily prove 

 them to be organic or marine, because we know very well that such bodies may 

 have become incorporated or introduced from without, during the formation of 

 she bed of clay from the debris of the chalk and other rocks. That such may be 

 the case, I think there cannot be any doubt, and I am supported in this view by my 

 friends Mr, J. W. Salter, Mr. T. Rupert Jones, and others. Mr Salter, moreover) 

 thinks such concretions are the commonest things in nature, and such a3 might be 

 expected in argillaceous matters c ntaining carbonate of lime. They have 

 assumed a flattened and compressed form, owing probably to pressure from the 

 surface above. I am free to admit, however, that the material forming these 

 concretions, may have become deposited aionnd some marine vegetable remains, 

 in consequence of the rather unusual forms assumed. In beds of clay employed 

 for economic purposes, numerous concretions, (assuming various forms, mostly 

 rounded, are very frequently found by the workmen, especially when the clay 

 contains much calcareous matter The workmen call them " race," and they 

 consist of quartz-sand, mica more or less decomposed felspar, peroxide of iron, 

 and a large proportion of calcareous particles, f The greater part, if not the whole 

 of the latter, Mr. C. H. Sorby, believes to have been derived from the chalk ; for 

 numerous characteristic fragments of the Foraminifera, of which that deposit is 

 almost entirely composed, are found in it. He thinks such concretions are formed 

 from a mixture of chalk and fine clay, and that they have become consolidated by 

 the action of carbonic water. Such, I conceive would be also an explanation of 

 the specimens from Tinge wick, with the possible exception of a form or shape 

 constituting a nucleus." 



COAL FIELDS OF KENTUCKY. 



The following remarks on the coal deposits of Kentucky, are extracted from the 



* We may mention here, that we have recently placed, in the collection of the Canadian 

 Institute, some peculiar, silicious concretions, (hitherto, we believe, unnoticed,) from the 

 Black River Limestone of Lake St. John, near the Indian Village of Rama, north-east of 

 Lake Simcoe, in Canada West. Some of these strikingly resemble bones of various kinds ; 

 and they present moreover, an internal cavity, often lined with a druse of minute quartz 

 crystals. Their concretionary chara"ter is, however, quite evident. One of the specimens 

 obtained, exhibits on its surface a strongly marked itnpression of the flat valve of an Orthis 

 —probably O.testudinaria, or O. costalis. It may also be mentioned in connection with 

 this su'oject, that the Palseotroehis of Emmons, a supposed fossil coral, has lately been 

 shewn by Professor Hall, to bo merely a concretionary structure. E. J. 0. 



f Quarterly Geological Journal, vol. 8, p. 186. 



