162 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [NoV. 21, 



j. Coal, 1 foot. 

 k. Grey marl, 3 feet. 



I. Coal, 2>\ to 4^ feet ; the only bed worked. 

 m. Grey marl, 6 feet. 

 n. Alternation of grey marl and white limestone. 



6 . A formation of great thickness, consisting of thin beds of bluish 

 earthy limestone alternating with blue marl, the beds varying from 

 six inches to two feet thick ; this series resembles in appearance our 

 blue lias : dip S.E. 40°. These beds are crowded with Ammonites, 

 some of which are above three feet in diameter, and other shells. 



7 . I did not see the beds underlying the above, but I was told that 

 on the north side of the Cape a red marl rose from beneath them. 



The organic remains found in the limestones Nos. 3 and 4, above \)£l^ 

 carboniferous series, are few in number, and of species which only serve 

 to indicate the middle part of the oolitic series ; they are as follows ; 



Corbula trigona, Roemer. Ostraea solitaria, Sow. 



Dianchora bicornis, n. s. Perna mytiloides, Lam. 



Mytilus Beirensis, n. s. Terebratula bisufFarcinata, Schlotheim. 



There appear to be six beds of coal known, forming a total thick- 

 ness of about ten feet ; the quality is bituminous, but it contains a 

 good deal of sulphur, which prevents its general consumption, and 

 the mines have only been worked on a small scale : the mines are 

 close to the sea, but the coast is too rough to allow the coal to be 

 shipped on the spot, and it is carted to Figueira for shipment. 



M. Michon, the director of the works, was kind enough to supply 

 me with every information concerning them, and to give me some 

 specimens of a Zamites, which was the only plant he had observed in 

 the beds ; it was found in the grey marl {m) immediately below the 

 principal bed of coal. I could find no traces of any other plants 

 among the rubbish of the mine. 



Mr. Morris has had the goodness to examine the specimens, and 

 finds it to be a variety of Zamites gramineus, a well-known species of 

 the carboniferous shales associated with the inferior oolite on the 

 coast of Yorkshire. His remarks on the subject will be found in the 

 Appendix. 



The following species were found in the beds of blue marl and 

 limestone No. 6, below the coal series ; they clearly prove that these 

 beds belong to the lower part of the oolitic series : — 



Terebratula Astieriana, B^Orb. Ammonites Henrici?, VOrh. 



Beirensis, n. s. Humphriesianus, Sow. 



decorata, Von Buch. macrocepbalus, Schlotheim. 



~ perovalis, Sow. modiolaris, Luid. 



Ammonites anceps, ReinecJce. oolithicus, D^Orb. 



Bakeriae, Sow. plicomphalus, Sow. 



Brongniartii, Sow. . Three species, supposed to be 



■ discus, Sow. undescribed. 

 hecticus, ReinecTce. 



Perhaps on farther examination, the sandstones which lie above the 

 coal series of Cape Mondego may prove to be identical with the red 

 sandstones below the Coimbra limestone. This seems the most pro- 

 bable classification of these detached masses of Jurassic rocks. 



