Maryland Geological Survey 33 T 



in the Lower Cretaceous and of the Caprinids, the Radiolitidae, the Hippu- 

 ritidae, the Ceratites and the Belemnite genera Duvalia and Belemnopsis, 

 and by the absence of Aucella, Inoceramus, Actinocamax and Belemni- 

 tella. 



The Upper Cretaecous beds of northern and central Europe occur for 

 the most part in five more or less distinct provinces which have in com- 

 mon a dominantly molluscan fauna. In this they all differ from the 

 clear-water fauna of the English chalk which is conspicuous for the 

 abundance of the Echinoids and is, for that reason, less comparable with 

 the Cretaceous of the Middle Altantic states than the continental faunas. 



The upper Matawan of Maryland has been tentatively referred to the 

 lower Campanian, although the paleontologic evidence for the correlation 

 is very meager. The single common ammonite, Scaphites hippocrepis, is 

 restricted in its European distribution to the lower zones of the Cam- 

 panian. Gryphcea vesicularis and Ostrea larva are also common to both 

 continents, but they range so widely that their occurrence is insignificant. 



The Monmouth fauna is comparable to that of the upper Campanian, 

 or Belemnitella mucronata zone. To be sure, none of the three character- 

 istic Monmouth cephalopods, Sphenodiscus lobatus, Scaphites conradi, 

 and Belemnitella americana, are represented in Europe by identical 

 species, but their analogues, Sphenodiscus lenticularis, Scaphites pulcher- 

 rimus, and Belmenitella mucronata, are so closely related that they have 

 been confused in the synonymies. Baculites anceps, one of the character- 

 istic Fox Hills species, is common in the Maestricht beds. Inoceramus 

 barabini of the Exogyra costata zone of the Gulf and of the Fox Hills has 

 been considered a varietal form of I. cripsii, so abundant in the upper 

 Campanian of England and the continent. Grypl\wa vesicularis and 

 Ostrea larva in some of its manifestations are common in the Campanian 

 as well as in the Santonian. None of the Monmouth forms represented in 

 Europe by identical or closely analogous species are restricted to a lower 

 horizon than the upper Campanian, excepting Eutrephoceras dekayi, a 

 species which in the Western Interior is restricted to the Pierre. 



There is little direct evidence for the correlation of the Rancocas with 

 the Danian, but the general facies of the faunas is strikingly similar. 



