(54) 



unrepresented in New Jersey. Hollick would consider it the 

 equivalent of the New Jersey Raritan, its distinctive char- 

 acters being due to morainal action, with which view I entirely 

 concur. 



From the evidence of the flora alone we would consider 

 the Matawan slightly more recent than the Raritan ; a direct 

 continuation of the latter, however, with several species added 

 which are unknown from the Raritan. Thus, aside from the 

 dissimilar species due to our imperfect knowledge of the flora 

 of the two formations it remains to be pointed out that the 

 occurrence of Nelwnho argues a somewhat later age for the 

 Matawan, as this genus is not found below the Belly River 

 Cretaceous on this continent.* Time must also have elapsed 

 for the development or introduction of the various species of 

 Stercidia which are found here as well as for the changed 

 species of Aralia. The scarcity (absence) of ferns, the ab- 

 sence of Brachyphyllum which is essentially a Lower Cre- 

 taceous genus, and the much larger leaved Moriconia all 

 point to a somewhat later time than the Raritan. 



The Matawan, then, represents the transition period from 

 the Lower to the Upper Cretaceous, when marine conditions 

 replaced fresh-water estuarine conditions ; and the flora is 

 undoubtedly the latest Cretaceous flora of the Atlantic coastal 

 plain which has been preserved. Professor Ward suggests 

 that this ancient coastal plain may have extended to Green- 

 land, but no evidence other than the remarkable similarity of 

 the floras is known. 



Just a word in regard to the remains. In common with the 

 vast majority of New Jersey Clay specimens, the Matawan 

 plants were hermetically sealed in the clay and slowly car- 

 bonized, so that when reexposed to the air, the thick sheet 

 of lignite dries, becoming cracked, and is soon dissipated, 

 leaving only a faint impression behind. This has for years 

 proved an obstacle to the proper investigation of these floras 

 and it is only with the discovery of leaf-layers carrying con- 



*Dr. Hollick has found AV/wwdo on Martha's Vineyard and Long Island, 

 the latter locality as yet unpublished, which vitiates the above statement. 



