1867.] 



TATE LOWER LIAS OP lEELAJfD. 



301 



Ammonites Turneri, as the case may be ; for they may range thi^ough 

 several zones. And the Ammonite which gives its name to a zone is 

 but one of many which mark a determinate stage in the life-history of 

 the formation. Hence the zone is a zoological one, and signifies an 

 assemblage of species, and not the range of an Ammonite; and, 

 whether you call it Lias a, Lias /3, &c., or the zones of Ammonites 

 plano7^his, Ammonites angulatus, &c., the succession of faunas in the 

 Lower Lias still remains patent, and it is to these several faunas 

 that the term " Ammonite -zone " is applied. 



I am of opinion that the Portrush rock belongs to the zone of 

 Ammonites planorlis. The fossils are few in number, and are some- 

 w^hat indeterminable ; and though I have carefuUy studied a large 

 series collected by the late E. MacAdam, E.G.S., and have observed 

 others in situ, yet I can only enumerate, from personal inspection, 

 six species as composing the fauna of the Portrush Eock. Portlock 

 cites 12 species from it: these are reduced by the elimination of 

 synonyms to 10 ; and one is given doubtfully as from that rock ; 4 of 

 the 9 have come under my observation, leaving 5 on that geologist's 

 authority. 



The species are : — Ammonites angulatus ! (very rare) ; A. JoJin- 

 stoni\ (very abundant) ; A.armatusl ; Pectenvimineus\; lAmaacuti- 

 costal; L.i'ustica?; My tilus minimus \ (coTa.m.oji); Avicula incequivalvis; 

 PJioladomya ventricosa ; Cardinia ovalis ! ; and Panopcea elongata. 



Table of the Fossils of the Zoira of AivnvroyiTES planoebis. 



No. 



Species of the Zone. 



Localities. 



Special 

 to the 

 zone. 



Passing to 



superior 



zones. 



1 

 2 

 3 



4 



5 



6 



7 



8 



9 



10 



11 



12 



13 



14 

 15 

 16 

 17 



18 



i\m.monites angulatus, Schloth. 



armatus ?, Sow 



Johnston!, Sow 



planorbis, Sow \ 



Ostrea irregularis, Milnst 



Pecten calvus Munst 



Portrush 



Portrush {Portlock) . . 



Portrush 



Waterloo; Whitehead; 



Grarron 



Colin ; Waterloo .... 



Waterloo 



Portrush 



Waterloo ; Portrush . . 

 Portrush {Portlock) . . 

 Portrush {Portlock) . . 



Waterloo 



Waterloo 





-X- 



it 



■$5- 

 i'r 

 -)t 



-x- 





Lima acuticosta, Munst 



Avicula inasquivalvis ?, Sow. . . 

 Perna infraliassica, Querist. . . 

 Gervillia acuminata, Tqin 



Mjtilus minimus, Sow \ 



Lucina cardioides, Phil., sp. . . 



Cardinia ovalis, Stutchb 



Pholadomya ventricosa (Juv.) . . 

 Panop^a elongata. Bom 



Hemipedina Bechei, Wr \ 



Waterloo; Whitehead; 

 Portrush; Colin Glen 



Waterloo 



Waterloo ; Portrush . , 

 Portrush {Portlock) . . 

 Portrush {Portlock).. 

 CoUn ; Whitehead ; " 

 Waterloo , ' 







Total 



3t 



13 



t I have not included species 2 and 9 in this enumeration, as they are 

 doubtfully determined. 



