204 PALAEONTOLOGY OF NEW JEESEY. 



under the genus Polortlms (by the two last authors Avritten Polarthus), but 

 I see no evidence from any of the remains which I have examined of its 

 generic identity with the Teredo tibialis of Morton, which is the species upon 

 which the genus Polorthus was founded, and I have, therefore, retained it 

 under the genus Gastrochoena, 



Formation and localities. — In the Middle Marl Beds at Timber Creek, 

 New Jersey. Mr. Gabbalso cites it from the ^'brown marls" of Burlington 

 County, New Jersey, from which place I have not seen them. 



