FROM THE ZONE OP AMMONITES ANGULATUS. 47 



The septa are very thin, and are faintly dentate ; they often curve and unite. They 

 reach well into the axial space, and are united by dissepiments. They are subequal, but 

 many rudimentary septa exist. There are not four complete cycles of septa. 



Diameter of calices jgths — ^ths inch. 



Locality. Long Coppice, near Binton, Warwickshire. 



In the Collection of R. Tomes, Esq. 



The delicacy and subequal character of the septa, their deficiency in decided den- 

 tations, and the dissepiments between the septa, characterise this species. 



There is an immense Isastraa at Inkbarrow, with small calices and thick walls ; unfor- 

 tunately it is not determinable specifically, but the honeycomb appearance and subgibbous 

 upper surface, and the low septal number, may distinguish it. A specimen is in the col- 

 lection of the Rev. P. B. Brodie, F.G.S. 



Isastrcea MurcJdsoni, Wright, is found attached to the Inkbarrow specimen, and thus 

 this Scottish Coral has also an English habitat. 



X. On the Corals of the British and European Lower Liassic Deposits op the 

 Zones of Ammonites angtjlatus, Ammonites planorbis, and Avicula contorta. 



The strata of the Lower Lias evidently contain more than one Coral-fauna, and there is 

 a strong distinction between the assemblage of species of the Zone of Ammonites Buck- 

 landi and those of the zones below. The Corals of the White Lias are few in number, and 

 probably belong to the genus Montlivaltia, but they cannot be distinguished specifically. 

 The Avicula contorta series of France and England are uncoralliferous, but the Italian beds 

 at Azzarola, which probably are on that horizon, contain a very remarkable Coral-fauna. 



The extent of the area of Coralhferous beds described by Stoppani as the Azzarola series 

 is very considerable. The " Madrepore-bed," as it is termed by Stoppani, is seen above 

 the Azzarola beds, with Cardiwm Bhceticum, 3Iyoplioria injlata, Mytilus psilonoti, Avicula 

 contorta, Terebratula gregaria, &c., wherever the succession of the rocks can be made out, 

 either on the south-eastern slopes of the Alps, as on the Lake of Como, or on the north- 

 western slopes to the south of the Lake of Geneva.^ The Madrepore-bed is described, more- 

 over, as occurring below and in the midst of the Azzarola beds, and as forming a dense layer 

 of eight to ten yards in thickness. The prevailing Coral is Rhahdophyllia Langohardica, 

 Stop., and the genus is represented by three other species. The Bhabdophyllics resemble 

 in their habit of growth many TUecosmilioe, and form in the Azzarola beds great masses 

 of tangle, like Thecosmilia Martini in the Coralliferous beds of the Cote d'Or and of 

 Cowbridge in South Wales. Stoppani describes a Stylina from some casts which 



1 Stoppani, 'Monog. des Foss. de 1' Azzarola.' 



