THE MARSHALLTOWN. 87 



ANALYTICAL LISCUSSION OF THF MARSHALLTOWN FAUNA. 



The data recorded in the above table may be summarized as 

 follows, in order to show the number of Marshalltown species 

 common to each of the other faunas in the series. Of the total 

 43 species recognized, 10 or 23 per cent, are restricted to the 

 Marshalltown fauna. 



Cliffwood, 7 



Merchantville, i8 



Woodbury, lo 



MARSHALLTOWN, 43 



Wenonah, i5 



Mt Laurel-Navesink , 20 



Red Bank, 13 



Tinton, 8 



Ripley Group, etc., 26 



In the above summary table a distinct alternation in the rela- 

 tionship of the faunas, already noted, is shown, the Merchantville 

 and Mount Laurel-Navesink faunas having more species in com- 

 mon with the Marshalltown than do^ the Woodbury and We- 

 nonah, although the latter twO' formations are immediately sub- 

 jacent and superjacent tO' the Marshalltown. The Tinton, how- 

 ever, does not in this table, show a closer relationship to the 

 Marshalltown than does the Red Bank, although it will be shown 

 later that the Tinton is much more closely allied to the Navesink 

 than is the Red Bank. 



The Cucidlaea. element in the Marshalltown fauna has a no- 

 table development, C. tippana being one of the most abundant 

 species at locality 177. Neithea quinquecostata and Cardium 

 temtistriatum are other conspicuous species of the Ciicullaea fauna 

 which are recurrent from the Merchantville and take a con- 

 spicuous place in this fauna. Axinea subanstralis, one of the 

 most characteristic members of the other manifestations of the 

 Citcullaea fauna, as well as Cucidlaea antrosa have not been ob- 

 served in any of the collections which have been studied from 

 the Marshalltown, although it is not improbable that they may 

 yet be observed in future collections. The following list shows 

 those species in the fauna which are recurrent from the Mer- 



