FROM THE ZONE OF AMMONITES BUCKLANDT. 51 



57. Isastraa Sinemuriensis, E. de From. South Wales ; France. 



58. — Condeana, Chapuis et Dewalque. Luxembourg ; France. 



59. — globosa, Duncan. South Wales. 



60. — Murchisoni, Wright. Isle of Skye ; Inkbarrow, England. 



61. — Tomesii, Duncan. Worcestershire. 



Of these 61 species 50 are found in the British Isles. 



XIII. Corals from the Zone of Ammonites Bucklandi (bisulcatus). 



Corals are not numerous in this zone, and the commonest species of the Zone of 

 Ammonites angulatus are not found in any of its strata. It is probable that Thecosmilia 

 Martini, E. de From., which in France ranges from the beds containing Ammonites 

 Moreanus into those in which Avimonites bisulcatus is found, has a corresponding vertical 

 distribution in England. Thecosmilia Michelitii, Terq. et Piette, appears to be present in 

 the Zone of Ammonites Bucklandi, but only in the form of casts, which resemble those 

 found at Abbott's Wood, in the Zone of Ammonites angulatus. These casts and some of 

 Tliecosmilia Martini have been assigned to the genus Cladophgllia, but without sufficient 

 reason. Tliecosmilia is a large genus, and the species contain individuals of all sizes, so 

 that to give to very small cylindroid Thecosmilice the term Cladophgllice is too artificial a 

 distinction. The septa of Thecosmilia are generally, but by no means universally, regularly 

 toothed, granular, and slightly exsert ; and the septa of Cladophgllia are said to be 

 small, not numerous, and slightly dentate ; moreover, the endotheca is scanty in 

 Cladophyllia, but abundant in Thecosmilia. These are not generic distinctions, and it is 

 very probable that one genus will absorb the other. 



Section— ^POi^O/y^. 

 Family— ASTR^JDyE. 



Division LiTHOPHYLLACEiE SIMPLICES. 



Genus — Montlivaltia. 

 1. Montlivaltia Guettardi, Blainville, 1830. PI. XII, figs. 10 — 14. 



The following is the specific diagnosis given by MM. Chapuis and Dewalque.^ 

 Corallum simple and rather variable in shape ; often conical, more or less depressed, 

 rarely cylindro-conical ; the base is slightly pedicillate. 



1 Chapuis et Dewalque, ' Descript. des Foss. des Terr. Second, du Luxembourg, 1854.' 



