﻿Ill 



BRITISH DEVONIAN BRACHIOPODA. 



to certain shapes of C. heteroelita. The absence, as far as my experience goes, in these 

 Irish beds, of any examples of ffliytichonetta laticosta, Strophcdosia producloida (or 

 caperdta, and Prod.pralongus — species so exceedingly abundant and characteristic of the 

 .North Devon and West Somerset ' Marwood and Pilton beds,' and which we have never 

 yet observed from any Carboniferous rock with which we are acquainted — is very remark- 

 able. On the other hand, out of about twenty-one species which have been hitherto 

 obtained from the ' Marwood and Pilton series,' nine or ten only occur also with 

 certainty in the Cork shales and grits above described ; while of the Marwood and Pilton 

 series, some twelve or fourteen out of the twenty-one occur also in the Carboniferous slates 

 and shales of different parts of Great Britain. 



It appears to me possible that, if the ' Coomhola series' is not exactly contem- 

 poraneous with that of Marwood and Pilton, it would at any rate be the regular con- 

 tinuation of these last-named beds, and thus form a regular passage or connection between 

 the Marwood and the Carboniferous slates and shales which possess only Carboniferous 

 species. It is, however, no positive proof that, because these ' Coomhola/ or Cork beds, 

 have not hitherto shown a trace of Rhynclionella laticosta, Strophalosia productoides, and 

 Productm prcelongus, the two rocks might not be of the same age ; for we must not 

 expect to find in every locality every species that is characteristic of the age of the 

 deposit, but the absence of these three forms in the Irish beds is certainly worthy of notice. 



With reference to the South Pembrokeshire series to which Mr. Salter attaches so 

 much importance I can add but little ; for the only Brachiopod I have seen from its beds 

 is a Disciua, found there by Mr. Salter, and now in the Museum of the Geological 

 Survey. It is the same as the Carboniferous Discina nitida, and occurs also in the 

 greenish shales or silty beds of the Marwood series. 



We will now add a few short observations on the geological, geographical, and 

 palacontological distribution of the species we have been able to examine from tin' 

 counties of Devonshire and Cornwall ; but for more ample geological information I must 

 refer the reader to the Memoirs by the Rev. A. Sedgwick and Sir R. Murchison, ' On the 

 Physical Structure of Devonshire,' Sir II. De la Beche's and Mr. Godwin-Austen's memoirs 

 on the same subject. Prof. Phillips's 1 Palaeozoic Fossils/ and Mr. Pengelly's paper " On 

 the Distribution of Devonian Fossils of Devon and Cornwall," published in the ' Annual 

 Reports of the Royal Society of Cornwall for 1800/ as well as to Mr. Salter's valuable 

 paper on the " Upper Old Red Sandstone and Upper Devonian Rocks/' published in 

 the Quarterly Journal of the Geol. Soc. for Nov., ] S63. 



North Devon and its coast-line from beyond the Foreland to the River Taw, or to 

 Brushford in Somersetshire, is one of considerable geological interest, and has been very 

 carefully examined by the Rev. F. Mules, of Marwood, Mr. Valpy, of Ilfracotnbe, 

 Mr. J. Hall, of Barnstaple, Mr. Salter, and others. The Rev. F. Mules kindly 

 forwarded for my inspection and guidance a detailed geological map of the district, in 



