266 DR. H. HICKS ON THE MORTE SLATES, AND [May 1 896, 



recently obtained, is submitted, I think it will be seen that it agrees 

 far more closely with that which has been made out in other areas 

 in the British Isles than has hitherto been suspected. 



VII. Description of the Fossils pound in North Devon. 

 Ltngtjla mortensis, sp. nov. (PI. X. figs. 1-5.) 



This is probably the largest Lingula yet found in the British 

 Silurian rocks, and it occurs very plentifully in the Morte Slates, 

 though usually in a distorted condition. Elongated oval, the sides 

 nearly parallel. Bather acutely rounded in front, and tapering 

 gradually backwards towards the beak. Valves compressed, and 

 surface marked with numerous fine lines of growth, which here and 

 there are sculptured with cross markings. 



Length 24, width 9 lines. 



In size and shape it more closely resembles L. Brodiei, Davidson, 

 from the Woolhope Limestone, than any other species described 

 from the British Palaeozoic rocks ; but it is larger than that species, 

 and longer in proportion to the width. As one specimen only of 

 L. Brodiei has been figured and described, it is possible, when others 

 have been discovered, that they may be found to agree more closely 

 with our shell, especially as they occur on the same geological 

 horizon. In association with the large forms there are others of 

 various sizes, and some of the surfaces are thickly covered with 

 minute specimens as in PI. X. fig. 5. 



Pound at Woolacombe, Morte Point, Lee, Mullacott, and Shelfin. 



Stricklandinia lirata, Sowerby. (PI. X. figs. 6-8.) 



This is the most characteristic fossil in the Mullacott quarry, but 

 though it occurs there in fair abundance it is most difficult, owing 

 to the crushing and cleavage, to obtain any good specimens. Those, 

 however, which have been found show that it attained a large 

 size, equalling nearly the largest forms found in the Wenlock Beds of 

 the Island of Gothland. 



According to Davidson, Stricklandinia lirata ' varies greatly in its 

 external shape. . . The size and regularity of the ribs are especially 

 variable in different specimens, as well as the length of the hinge- 

 line.' (Monogr. Pal. Soc. ' Brit. Sil. Brachiop.' vol. iii. pt. vii. p. 161.) 



The suggestion first made to me by Mr. Sharman, of the Museum 

 of Practical Geology, that our fossil seemed more closely allied to 

 S. lirata than to any other brachiopod with which he was acquainted, 

 tempted me to make an examination of many of the specimens in our 

 museums ; and the fact, stated by Davidson, of its tendency to vary 

 greatly in shape and ornamentation I found very true. I cannot 

 say that, so far, I have been able to exactly match our fossil with any 

 other specimen, but undoubtedly it approaches most closely in its size 

 and ornamentation the specimens in the Society's Museum and in the 

 Jermyn Street Museum, from the lowest beds of Wenlock age at 

 Marloes Bay, Pembrokeshire, and those from Gothland in the Natural 

 History Museum. The following characters, abstracted from those 



