82 ^ CRETACEOUS PALEONTOLOGY. 



same horizon in his "Trigonia Hmbata zone," his T. limbata 

 being the shell recognized in this report as T. thoracica. Cred- 

 ner's chief locality was in a railroad cut near Woodbury, which 

 afforded him an abundance of fossils at the time of his visit, 

 prior to 1870, but although a careful search has been made for 

 this locality during the recent operations of the Survey, it has 

 not been detected. From an exicavation near Wenonah, made 

 some years ago, a marly clay filled with well-preserved fossil 

 shells has been reported, which could only be the Marshalltown, 

 although no collections were secured from there by the writer. 

 Formerly, when the marl pits were being actively operated near 

 Marshalltown, an abundance of fossils could be secured there, 

 but none could be obtained during the prosecution of the field 

 work in connection with the present report. From time to time 

 in the future, however, these or other localities in the region will 

 doubtless be opened up, and additional collections should be 

 secured for comparative study. 



Of the four localities, a record of whose faunas are here given, 

 only one has been carefully worked. At locality 177 the better 

 part of two weeks time was spent in an attempt to make as 

 complete a collection as possible, while not over one hour was 

 spent at either of the other three localities. In the case of the 

 Marshalltown fauna, therefore, the recorded number of occur- 

 rences is not of so great importance as in the case of the faunas 

 of those formations from which a larger number of careful col- 

 lections have been made. However, those species which do occur 

 at several of these localities may be safely considered as being 

 among the conspicuous members of the fauna. 



The local faunas which have been studied are as follows : 



Locality ly/. — By far the most important fossiliferous local- 

 ity in the Marshalltown formation, from which collections have 

 been secured during the recent operations of the Survey, is about 

 I mile a little south of west from Swedesboro. Tbe clay is well 

 exposed in the banks of the brook in the woods at this locality, 

 and the condition of preservation of the shells is exceptional for 

 the Cretaceous beds of New Jersey, the shell substance itself be- 



