1871.] JtTDD — PUNPIBLB FOKMATION. 211 



and deliglit recognized in them the fauna of the coal-bearing beds 

 of Utrillas, in eastern Spain, which has of late years been made 

 known to us by the works of Yilanova, de YerneuU, Coquand, 

 CoUomb, and de Loriere. I should, perhaps, mention that in 

 1850 no description of these Spanish beds had, so far as I know, 

 appeared. 



Believing the subject one worthy of careful study, I have devoted 

 my attention to it for some time past, and embody the results in the 

 present memoir. In the execution of my task I have been furnished 

 with much valuable information and advice by Sir C. Lyell, Mr. 

 Godwin-Austen, Mr. Hulke (who in 1866 examined the beds and 

 made a collection from them), Mr. "Wilcox, of Wareham, and my 

 colleagues Messrs. Etheridge, Bristow, and Whitaker. 



At the late Meeting of the British Association, I gave a general 

 resume oi the subject; and in the recently pubUshed work, 'Student's 

 Elements of Geology,' Sir C. LyeU has referred to the beds and 

 figured one of their most characteristic fossils. 

 » 



III. Sections in the Isle of Ptjkbeck. 



At the northern part of Swanage Bay, and immediately below the 

 great chalk ridge of Ballard Down, is a little recess in the cUifs 

 called Punfield Cove (fig 1)*. It is at this point that we find the 

 most interesting exposure of the strata which I propose to describe. 

 Regarding this, therefore, as a typical section, and deriving the name 

 of the formation from the locaHty, I proceed in the first instance to 

 give a detailed account of the succession of beds at this point. 



1. Punfield Cove. The strata seen here, in descending order (the 

 whole being nearly vertical), are : — 



(1) Upper Chalk with Flints. 



(2) Lower Chalk without Flints. 



(3) Chalk Marl. 



(4) Upper G-reensand, with a poor representative of the Gault Clay towards 

 its lower part, the whole being about 100 feet thick. 



(5) A representative of the " Lower Greensand," consisting of grey clays 

 alternating with ferruginous sandy beds, generally destitute of fossils, but 

 yielding Ilxogyra sinuata. Sow., and Panopma neocomiensis, d'Orb. The 

 formation is not more than 60 feet thick, and thus exhibits a great 

 diminution from its equivalent in the Isle of Wight. This result is partly 

 due to thinning out, and partly to overlap. 



Immediately below we find the series of fluvio-marine beds, which 

 I propose to include in the Punfield formation (see vertical sec- 

 tions, fig. 2) : — 



A. Dark blue, finely laminated shales, in part cypridiferous, with 

 thin bands of limestone made up of Gyrena, Ostrea, &e., and fibrous 

 carbonate of lime ( " beef" or " bacon " ), like that of the Purbecks. 

 According to Mr. Godwin-Austen these beds are only a few feet 

 thick. At the present time they are completely hidden by the 

 debris from the beds above, and I have never yet had an opportunity 

 of seeing them in situ. They appear, however, to resemble in 



* See also Sir Henry Englefield's 'Isle of Wight' (1816), plate 29, no. 1. 



