VINCENTOWN FORMATION. 171 



as that of the shell layer at the summit of the Hornerstowrl marl, 

 and, as has already been pointed out, this shell layer should, per- 

 haps, be considered as the base of the Vincentown' rather than 

 as the top of the Hornerstown. The most extensive fauna of 

 this sand facies has been collected near Deal (lyocality 122), from 

 near the summit of the formation, where, associated with T. 

 harlani, by far the most abundant member of the fauna, are 

 several species of pelecypods, of which species of the genera 

 Ncmodon, CucuUaea and Axinm are somewhat closely related to 

 members of the same genera in the lower faunas. Scattered 

 through the Vincentown sand, fragments of bryozoa and spines 

 of echinoids are not infrequently met with, forms which belong 

 rather to the calcareous facies of contemporaneous age. At one 

 locality on the Manasquam River west of Farmingdale (Locality 

 134), although the bed is arenaceous, but with a higher content 

 of glauconite than usual, the fauna is essentially the bryozoan 

 and echinoid fauna of the typical Vincentown calcareous beds. 



The fauna of the Vincentown limesand is unique among the 

 Cretaceous faunas of New Jersey. Calcareous bryozoans are 

 abundant, in some beds constituting locally a very large per- 

 centage of the total calcareous matter, no less than 54 species 

 of these organisms being recognized in the fauna at one locality 

 near Vincentown. Associated with these bryozoans are many 

 echinoids, and large numbers of shells of foraminifera. In other 

 localities where the bryozoans and echinoids are less conspicuous, 

 or nearly absent, Gryphaeostrea vomer, a species commonly pres- 

 ent in the Marshalltown and Navesink faunas, is the most con- 

 spicuous member of the fauna, associated with which Polorthus 

 tibialis is frequently present. In the denser limestone layers of 

 the formation at some points, several species of pelecypods and 

 gastropods are present, but on the whole, the molluscan element 

 in the fauna is not large in the number of species. Some of the 

 species of molluscs, such as Cardium knappi and Caryatis veto, 

 occur alsO' on the subjacent Hornerstown marl and in the super- 

 jacent Manasquan marl, although in the main the species of the 

 entire Vincentown are different from those of the Hornerstown 

 and the Manasquan. 



