BOTANICAL DISCUSSION. 



BOTAISTICAI, RELATIONSHIPS OF THE FLORA. 



If the entire flora is regarded from the standpoint of the subkingdoms repre- 

 sented, it may be seen that the Pteridophyta form a very insignificant element, and 

 this is true not only in the number of species but also in the actual number of speci- 

 mens collected. Six species, included in 5 genera, are all that we have thus far 

 been able to identify, and most of these are fragmentary, whereas in the Amboy 

 clays at least 10 species of ferns alone are known and several of these occur in con- 

 siderable abundance at certain horizons which we have reason to believe are repre- 

 sented in the insular formations. Recent discoveries of ferns in new exposures at 

 Kreischerville, Staten Island, point strongly in this direction and indicate that 

 additions to the pteridophytic flora may be expected from this locality when the 

 exposures have been more fully examined. 



In the Spermatophyta, in a total of 91 genera and 216 species, the gymnosperms 

 and angiosperms number 14 genera and 27 species and 77 genera and 189 species, 

 respectively. In the former 2 species are regarded as belonging to the Cycadales 

 and the remainder to the Coniferales, while the angiosperms are represented by 4 

 genera and 4 species of Monocotyledones, and 73 genera and 185 species of Dicotyle- 

 dones. The occurrence of the former class at the Long Island and Marthas Vine- 

 yard localities may possess some significance, inasmuch as not a single species 

 which could be included in it has as yet been found in the Amboy clays, although 

 some questionable remains are described from the Cliffwood clay marls. 



The greatest interest naturally centers around the Dicotyledones, in which 146 

 species are included in the Choripetalae, 16 in the Gamopetalse, and 23 are regarded 

 as of uncertain relation. The Ranales is the largest order, including 5 families, 

 16 genera, and 55 species. Of these the largest family is the Magnoliaceae, with 3 

 genera and 22 species, and the largest genus, Magnolia, with 14 species. 



The occurrence of several aquatic and semiaquatic plants, such as Nelumbo, 

 Marsilea, Typha, and Cyperacites, is interesting for the reason that they appear to be 

 confined to Long Island and Marthas Vineyard, and may indicate either that pecul- 

 iar local conditions prevailed there or else that they are elements of a flora belonging 

 to a different horizon from any known on Staten Island. 



It is unfortunate that the botanical relationships of some of the most abundant 

 and characteristic elements should be in doubt, but there is no question that^the 

 facts are not yet at hand with which to satisfactorily determine the systematic posi- 

 tion of the species included under such genera as Liriodendropsis and Williamsonia. 



MON L— 06 8 113 



