122 



KEY. J. E. CROSS ON THE GEOLOGY OE N.W. LINCOLNSHIRE. 



And, lastly, capping this clay, there is but one formation more ; 

 and that is either Forest marble or Cornbrash, probably the latter. 

 It is pretty well determined by its two Ammonites (A. macrocephalus 

 and Herveyi), by its two Terebratulce (T. lagenalis and obovata), and 

 by the rest of its fauna generally. One of its Trigonice (Moretoni) 

 appears in great beauty, and has been figured in Dr. Lycett's work ; 

 and a second species, pronounced by him to be new, will, I believe, 

 appear in his forthcoming publications. There is one other new 

 bivalve to which I would direct attention — a little costated Opis. 

 There are two figures in Phillips's 'Geology of Yorkshire,' both 

 termed " Cardita similis" one from the Coralline Oolite, the other 

 from the Dogger, which somewhat resemble it ; but it is hardly 

 possible that either of them can represent the shell to which I 

 refer. 



Cornbrash occupies the surface of the ground eastwards until the 

 level alluvium of the plain of the Ancholme draws a final veil over 

 all researches. Further eastward I do not propose to pass : 

 indeed, in a direct easterly line we find nothing Oolitic ; east of the 

 alluvial plain of the Ancholme, chalk-rubble covers all, till the high 

 Chalk wold raises itself above it. A little further south the Kim- 

 meridge Clay shows itself between, but not so just here. And with 

 the mention of this my task is done. I have exhibited (in a very 

 imperfect and unsatisfactory manner, I fear) my panorama of the 

 North Lincolnshire Lias and Oolites ; and if I have happily succeeded 

 in interesting my hearers at all it will be, I am sure, only because 

 of the novelty of the Ultima Thule I have treated of. I hope 

 more competent observers may think it worth while to come upon 

 the scene and to check the crude views that have been advanced by 

 me here. If on any point these views should be found to be 

 erroneous, I can only say no one will rejoice more than myself that 

 the actual truth should be elicited. 



Lowest Lias. 



Valley of 



Ammonites Jobnstoni, Sow. 



angulatus, Schloth. (var. cate- 



natus, D'Orbigny, var. moreanus, 



D' Orbigny. 

 Nautilus striatus, Sow. 

 Pleurotomaria basilica? (Chap.) 



, sp. 



psilonoti, Quenst. 



Turritella Deshayesia ?, Terq. 

 Cardinia crassissiraa, Ag. 



Listeri, Sow. 



, oval sp. 



Astarte obliqua, Desk. 

 Pleuromya Dunkeri, Rom". 

 Myacites liasinus, Ziet. 

 Homomya, sp. 

 Pholadomya prima, Quenst. 

 Cardita Heberti ?, Terq. 

 Modiola nitidula, Dunk. 



the Trent. 



Modiola, sp. 



Area, sp. 



Unicardium eardioides, Thill. 



Avicula decussata. 



Lima gigantea, Sow. (var.) 



Hermanni, Voltz. 



hettangiensis, Terq. 



, small ribbed sp. 



Pecten valloniensis ? (doubtful). 



, small smooth sp. 



Gryphaea, n. sp. 



incurva, Sow. (var.). 



Ostrea irregularis, Gold/. 



rugata, Quenst. 



liassica, Strickl. 



Carpenteria (Terquemia). 

 Pentacrinus. 

 Spines of Cidaris. 

 Montlivaltia Haimei, Chap. 



