80 STUART WELLER 



being the lowest horizon where the Belemnitella fauna has been seen 

 in New Jersey. 



With this interpretation it is possible that both the terms, "Mount 

 Laurel" and "Wenonah," should be retained in the nomenclature 

 of these beds, the Wenonah for the sand formation beneath the beds 

 bearing the Belemnitella fauna in Monmouth County and for the 

 southern continuation of the same beds, while the name "Mount 

 Laurel" will designate the arenaceous facies of the Navesink which 

 becomes more and more conspicuous to the south. These relations, 

 however, complicate the task of mapping the beds in the southern 

 portion of the New Jersey area, because of the juxtaposition of the 

 two arenaceous formations whose separation can be based only upon 

 the presence or absence of the Belemnitella fauna. However, further 

 observations upon these beds must be made before the relations here 

 suggested can be considered as established. 



The fauna of the Red Bank sand is to some extent a recurrence 

 of the faunas of the beds beneath the Navesink marl, Trigonia 

 eufaulensis, Axinea mortoni and other species of the Merchantville, 

 Woodbury, and Wenonah formations being commonly present. 

 Some species, such as Perrisonota protexta and Corbula crassiplica, 

 which were present, although usually rare, in one or more of the 

 " clay-marl" formations, become much more abundant in the Red 

 Bank. The fauna is characterized everywhere by the large shells 

 of Gryphaea vesicularis and by Ostrea larva, species which were 

 abundant in none of these lower formations except the Marshalltown ; 

 but they never form such a shell bed as that which occurs so commonly 

 in the midst of the Navesink marl. Other elements in the fauna are 

 also inherited from the Navesink, although the two most character- 

 istic Navesink species, Belemnitella americana and Terebratella plicata, 

 have nowhere been observed in the fauna. 



In none of the classifications as published, except Cook's, is any 

 special recognition given to the hard, glauconitic, indurated sand 

 bed at the top of the Red Bank, although it was briefly referred to 

 by Clark, and has been carefully mapped by Knapp. This bed, 

 called by Cook the "indurated green earth," marks a definite horizon 

 and yields a fauna which especially characterizes it throughout its 

 entire extent. The most characteristic member of this fauna is the 



