60 CRETACEOUS PALEONTOLOGY. 



Cliffwood 16 



MERCHANTVILLE, 102 



Woodbury, 48 



Marshalltown 18 



Wenonah, ' 35 



Mt. Laurel-Navesink, 28 



Red Bank 19 



Tinton, II 



Ripley Group, etc., 44 



This table does not exhibit the distinct alternation in the occur- 

 rence of the larger number of common species which was so con- 

 spicuously shown in the similar table for the Cliffwood fauna. 

 The proper relationships of this fauna, however, are not clearly 

 shown by this table, because the extensive collections which have 

 been made in the Merchantville from one or two localities, have 

 in many instances brought to light single individuals of species 

 which occur abundantly in the Woodbury and more or less fre- 

 quently in the recurring phases of the same fauna, but which 

 are a negligible element in the Merchantville. Of the total 102 

 species recognized from the Merchantville, 44 have been noted 

 from but a single locality, many of these being represented by 

 single individuals, while 19 more are known from but two locali- 

 ties. As a whole the species which are common to the Merchant- 

 ville and Woodbury fall into two groups, one group of species 

 which occur rarely in the Merchantville and more commonly in the 

 Woodbury, and a second group of species which occur more or 

 less abundantly in the Merchantville and rarely in the Wood- 

 bury. When the more conspicuous elements in these two faunas 

 are compared, it is found that they are distinctly different. The 

 large number of species common to the two faunas, therefore, does 

 not prove their complete unity, but rather demonstrates that, 

 while living contemporaneously, they were not separated by an 

 impassable barrier, that they occupied adjacent areas where 

 somewhat different physical conditions obtained, and that occa- 

 sionally a species best adapted to one environment wandered into 

 the area of the other. 



Notwithstanding the large number of species present in the 

 Merchantville fauna which are more normally members of the 

 Lucina cretacea fauna, there is a distinct element which is re- 

 current in the Marshalltown, Mount Laurel-Navesink, and Tin- 

 ton, as may be seen by the following list. 



