18G6.] DUK-CAy — INPEA-LIAS CORALS OP SOUTH WALES. 19 



sp. It is not to be found in the Sutton Stone, nor in the Southern- 

 down or Brocastle beds, and it has not been discovered in any of the 

 continental strata which are presumed to be the equivalents of the 

 Ammonites-jylanorbis zone in Great Britain. 



There are three species of Monilivaltia in the "White Lias, but 

 they are indeterminable. 



The AvicuJa-coniorta beds at Beer Crowcomb were found by Mr. 

 Moore to contain a MontUvaltia with five cycles, but nothing more 

 could be made of it. As far as it is possible to judge, none of 

 these Montivaltice resemble those of the Sutton Stone or Brocastle 

 beds. The succession of rocks from the Trias to the top of the Pla- 

 norbis -series is complete ; and consequently, from stratigraphical and 

 palseontological data, the coralliferous beds at Sutton and Brocastle 

 cannot be intercalated amongst them. It is therefore necessary 

 to determine the continental equivalents of the beds under con- 

 sideration. 



6. Strata in France and in the DucJiy of Luxembourg w7iic7i have 

 the homotaocis of the Brocastle, Eiuenny, Sutton, and Southerndown 

 series. — In l^ormandy there is a considerable development of beds 

 which rest more or less upon depressions in quartzite rocks and 

 upon the Trias, and which are covered, conformably in some places, 

 but unconformably in others, by the Lias with Gryjihcea incurva*. 

 These beds occupy, in the east of the Cotentin, two small basins, 

 which are separated by the ridge of the quartzite rocks of Monte- 

 bourg ; and they can be traced to rest conformably on the Trias, and 

 partly on the granitic surface. The beds have been classified in 

 three divisions by M. Deslongchamps. The lowest are sandstones 

 and dolomites with impressions of plants ; the fossils are few in 

 number and are badly preserved ; and Mytilus minutus occurs, with 

 imperfect specimens of Avicula contorta. The middle are marls, 

 with Mytilus minutus, Mytilus liassinus, Tqm., Ostrea anomala, 

 Tqm., Diademo'psis seriale. The upper beds (the Calcaire de 

 Valogne), consist of two series : the lower contains Cai^dinia con- 

 cinna, Cardinia regularis, Tqm., Lima Valoniensis, Defr., Pecten 

 Valoni-ensis, Defr., Ostrea anomala, Plicatida Baylei, Tqm., Hettangia 

 securiformis, Tqm., Pleurotomaiia ccepa, Desl. 



The upper series has a lumachello with small Gasteropods at its 

 base. The following is a list of the specific forms : — 



Neritina arenacea, Tqon. 



Hettangensis, Tqm. 



Turritella Dunkeri, BimJc, sp. 



■ Zenkeni, Dunk., sp. 



Cerithium acuticostatum, Tqon. 



Jobte, Tqm. 



Phasianella nana, Tqm. 

 ■ — ■ — Morencyana, Pietie. 

 PHcatula Baylei, Tqm. 



Ostrea anomala, Tqm. 

 Septastrsea excavata, de From. 

 Thecosmiha, sp, 

 Melania unicingulata, Tqm. 

 ■^ — usta, Tqm. 

 AmpuUaria gracilis, Tqm. 

 Hettangia securiformis, Tqm. 

 Cardinia copides, de Et/cM. 

 Montlivaltia, sp. 



The uppermost beds in the Calvados contain Cardinia copides ; 

 and their upper surface is extremely hard, and more or less 



* Deslongchamps, Mem. Sec. Linneenne de Iformandie, vol. xiv., 1864, 



c 2 



