122 bulletin: museum of comparative zoology. 



nastrcea cyathiformis (Duncan), are also found in the Cambridge Eocene, 

 and are Eocene species. 



There are several species of corals in our collections from Jerusalem 

 Mountain, including, according to Vaughan, a Cladocora, — a genus not 

 hitherto found fossil in the West Indies. Vaughan remarks that there 

 are other undetermined species from the Cretaceous of Jamaica different 

 from those already reported by Duncan. Nowhere in the Continental 

 American Cretaceous, except in Southern Mexico described by Felix 

 and Lenk, is there a diversified coral fauna, and the latter belongs to 

 lower beds. No comparison has been as 3'et instituted between the 

 Mexican-Jamaican Cretaceous corals, however. 



The MoUusca, with the exception of the Rudistes, are very poorly 

 represented. The eight genera of Gastropoda found are all poorly pre- 

 served casts, mostly from the Jerusalem beds, with the exception of 

 Actaionella, which also occurs in the Logic Green. The four pelecypods 

 other than tlie Eudistes are mostly from the upper marls of the Jerusa- 

 lem beds. This faint representation of Pelecypoda in the Cretaceous 

 of Jamaica is a most remarkable feature. Numerically the fauna is 

 predominantly Rudistean ; these forms always occur in all the fossilif- 

 erous beds, even when others are unrepresented. They compose the 

 mass of the Jerusalem limestones, and occur singly in the occasional 

 clay beds of the Ballard and Catadupa beds. 



Specimens of this Rudistean fauna collected by Nichols have re- 

 cently been described by Whitfield.^ It is unique in specific features, 

 being entirely different from that of Europe and North America, 

 especially that of Texas, where Rudistes are very numerous in the Ed- 

 wards formation of the Lower Cretaceous (unless R. nicholassi is «,llied 

 to a form of the Upper Cretaceous of Alabama and Texas). The 

 absence of the genus Hippurites, so abundant in the Upper Creta- 

 ceous of Europe and Southern IMexico, is also noticeable, although this 

 genus is missing from the Cretaceous of the United States. One 

 genus, Rarrcttia — included in the Rudistes by Woodward,^ and re- 

 cently asserted by Wliitfield ® not to belong in this group at all — has 

 no known representation elsewhere with the possible exception of 

 Guatemala, where it has been questionably reported by Sapper."* 



1 Bull. Am. Soc. Nat. Hist., New York, 1807, Vol. IX. 



2 The Goologist, London, 1862, Vol. V. pp. 372, 377. 



8 liull. Am. Soc. Nat. Hist., New York, 1897, Vol. IX. pp. 233-246, Plates 



xxvn.-xxxvin. 



* lieported by Sapper from Guatemala. Physical Geography of Guatemala. 

 Petcrmann's ISIitteilungcn, No. 113, Gotha, 1894, p. 9. 



