MANASQUAN MARL. 175 



PEIwECYPODA. 



Ostrea bryani Gabb. 

 Caryatis veta Whitf. 

 Teredo sp. 

 Polorthus tibialis (Mort.). 



VerTEbrata. 



Shark's teeth. 

 Fish vertebra. 



ANALYTICAL DISCUSSION OE THE MANASQUAN EAUNA. 



As shown in the Hsts of species collected from the above 

 localities, the fauna of the Manasquan marl is totally different 

 from the faunas of the beds lying below the Hornerstown marl. 

 There is, however, a distinct recurrence of species from the Hor- 

 nerstown. One O'f the conspicuous elements in the fauna are the 

 small, simple, horn corals, of which three species are recognized, 

 one of the most common, of them, Plabellum mortom, being also 

 present in the Hornerstown. Terebratidina atlantica and Caryatis 

 veta are two other species O'f the Manasquan fauna which occurred 

 earlier in the Hornerstown marl, and of these three species only 

 Caryatis veta has been observed in, the intervening Vincentown 

 formation. Although the known fauna of the Manasquan is 

 larger than the yet known fauna* of the Hornerstown marl beneath 

 the shell layer at the summit oif that formation, yet the evidence 

 seems -to- be sufficient to permit the assumption that the Mana- 

 squan fauna in its essential characters is a recurrence of the fauna 

 of the Hornerstown, with some modifications of course, due tO' 

 the recurrence in the same region of similar physical conditions. 

 The fauna had doubtless persisted somewhere in the adjacent 

 Cretaceous sea, where the physical conditions were favorable for 

 it, during the entire intervening time. 



