CRETACIC PERIOD 589 



Europe to America, and as all our species lived near the coast this migration 

 should have been effected largely by means of a continent or a series of islands, 

 instead of the present Atlantic ; perhaps a study of the fauna of Jamaica will 

 demonstrate later that that place was one of the stations on the road over which 

 the animals came. 



"In Europe the Gosau strata represent a mediterranean facies, and are nota- 

 bly distinguished in their paleontological character from the Senonian of the 

 north of Europe. In America we observe a surprising analogous circumstance. 

 We have known for some time that the Cenomanian strata of Mexico and Texas 

 represent a mediterranean facies, but the Senonian also represents an analogous 

 facies in Mexico (and Jamaica ?). In northern United States — that is to say, 

 in New Jersey — is found, according to Credner, a facies of the Senonian which 

 corresponds closely with that of the northern part of Europe; on the other 

 hand, the fauna described in this work represents a facies which corresponds 

 fairly well with that of Gosau, in the way that the facies of the Senonian of 

 northern America corresponds with that of the north of Europe." 



The Cardenas fauna has little in common with the Cretacic of the 

 United States. Of the Colorado, there is present Inoceramus labiatus, 

 I. fragilis, and I. cf. simpsoni (also in Montana series), and of the Mon- 

 tana Ostrea glabra, Anomia argentaria, A. gryphorhynchus, Gryphcea 

 vesicularis, and Exogyra costata. The wide differences between the Cre- 

 tacic of Mexico and that of the United States may be due in part to the 

 decided limestone facies of the former region and perhaps more to 

 latitude. 



The Colorado or Turonian faunal equivalents of Mexico have as yet 

 not been described, other than the few forms mentioned above. 



Antilles. — On Jamaica, the oldest fossiliferous formations are those of 

 the Blue Mountain series of about 5,000 feet thickness, with the base not 

 seen. The Lower Division is Cretacic, while the Upper Division, or 

 Eichmond beds, is of Eocene age, according to Hill. 250 There are tuffs 

 with some hard limestones and yellow clay, but most of the material "can 

 be traced to igneous rocks," deposits of a shallow sea, a "tangled series of 

 tuffs and conglomerates." 



In the lower part of the Lower Division the dominant fossils are 

 rudistids, Actaonella, and corals. The corals which have been described 

 are: Cladocera jamaicensis, Dtploria conferticostata, Multicolumnastraia 

 cyathiformis, Cyathoseris liaidingeri, Porites reussiana, and Leptophyllia 

 ugassizi. Of rudistids, there are Barrettia moniliformis, Radiolites (5 

 species), Caprina jamaicensis, Caprinella quadrangularis, C. occidentalis, 

 and C. gigantea. Some of the rudistids are said to occur in the Upper 



230 Hill : Bull, of Museum of Comparative Zoology, vol. 34, 1899 ; also see Gregory, 

 Quarterly Journal of the Geological Society of London, 1895, pp. 255-310. 



