12 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [NoV. 9, 



Bijjlorla crassolamellosa, Edw. & Haime, and Cyathoseris Haidingeri, 

 Eeiiss, of the Upper Clarendon Chalk, are common forms in the 

 Kriedensmerle, which, ^dth its associated Hippurite-limestone, was 

 first brought before the notice of geologists in the classical essay on 

 the Eastern Alps by Professor Sedgwick and Sir Roderick Mui'chison, 

 and the organic remains of which have been so ably described and 

 figured by Reuss, of Vienna. The minority have yielded a species 

 allied to the small-caliccd Heliastrseans of Gosau, and a species of 

 Pontes which is the oldest on record. There is a community of 

 species of corals between the Lower Chalk of Gosau and Piesting 

 and the French Hippurite-limestone at Martigues, the Corbieres, and 

 Uchaux. It is clearly this assemblage of forms which is represented in 

 Jamaica ; and it is an interesting fact that the specimens from Gosau, 

 Mount Hindmost, and Trout Plall present the same mineral aspect ; 

 in fact, the specimens are barely to be distinguished. 



This Lower Cretaceous coral-fauna is very rich in species, almost 

 equalling the Miocene ; it is peculiar to the horizon of the Lower 

 Chalk with ffijyj^urites, and its forms determine the age of the Cla- 

 rendon strata as significantly as their Rudistes. The strata yielding 

 the corals are of the same horizon as those which first yielded the 

 Barretfia and the Acteonella, although great masses of intrusive 

 rocks and some distance separate them. It is very probable that 

 the Hippuritic limestone exists in the neighbouring island of San 

 Domingo ; and it will be found in a former communication that 

 corals were noticed in Miocene strata there with very decided Lower 

 Cretaceous affinities, as well as in Jamaica *. The Astrocoenia deca- 

 phylla, a well-known coral of the European Lower Chalk, was noticed 

 as having been found by Mr. Barrett in the Jamaican Miocene ; and 

 Pliyllocoenia scidpta, an equally well-known species from Gosau and 

 Uchaux, was found in the Nivaje shale of San Domingo : moreover, 

 four other species, whose affinities are decidely Turonian, were 

 described from this last locality. Some of the specimens of these 

 erratic species are so mineralized as to lead to the belief that they 

 are derived fossils, whilst others resemble those of unquestionably 

 Mid-tertiary age. The derived appearance is much more decided 

 in the San-Domingan specimens than in those from Jamaica ; and as 

 the Lower Chalk is present in the latter island, it is very probably 

 to be found in the former. The formation would appear to be pre- 

 sent in the island of St. Thomas, where Dr. S. P. Woodward asserts 

 that the shell Acteonella Icevis was found ; but as yet it has not 

 been recognized in any other of the Antilles, neither has it been 

 discovered on the mainland. The Cretaceous formation of Trinidad 

 is identical with that of the adjacent part of South America ; it is 

 of Neocomian age, and is subordinate to an immense Mid-tertiary 

 series t- ^^ North America, where the Upper Greensand and the 

 Upper Chalk exist, the Lower Chalk has not yet been found. 



It follows that the Hippuritic and Coral-bearing limestone of 



* " West Indian Fossil Corals," Quart. Journ. Geol. Soc. vol. xis. p. 406. 

 t E. Etheridge, in Geol. Surv. of Trinidad, by G. P. Wall & J. G. Sawkins, 

 1860, p. 161. 



