446 THE AMERICAN NATURALIST [Vol. XLl 



sometimes small and inconspicuous, or prominent and extending 

 downward so as to enclose the petiole as in Acer saccharinum 

 Wang.; the sinuses broad and shallow; the terminal lobe with 

 two large, lateral teeth; the lateral lobes with one or two large 

 teeth on the lower side; the teeth acute, rarely somewhat acumi- 

 nate toward the summit. 



HoUick ('06, 234) has recently observed the occurrence of maple 

 fruits in the Pleistocene of Maryland, but it is at present impos- 

 sible to connect them definitely with any of the recognized leaves 

 or wood so far studied. 



Carya alba Nutt. — Although never abimdant, the leaves of the 

 hickory have been noted in three former collections from the Don. 

 Their form and \enation are so characteristic as to leave little 

 room for doubt as to their true character. 



Hollick ('06, 221, 222) now records the occurrence of three 

 species, one from the Talbot and two from the Sunderland For- 

 mation of Maryland. Only one of these is specifically recogniz- 

 able, and to this the name Hicoria pseudo-glabra, Hollick, is 

 assigned. 



Cercis canadensis L. — The red-bud, an altogether new constitu- 

 ent of the Don flora, is represented in the present collection by a 

 few leaf fragments which are nevertheless sufficient to establish 

 the identity of the species. 



Cyperus sp. — Fragments of jointed stems showing a finely 

 striated surface are referable to the genus Cyperus without specific 

 differentiation. Such fragments are of common occurrence in 

 material from the Pleistocene, and they possess little or no signi- 

 ficance with respect to a knowledge of climatic conditions. 



Gleditschia donensis n. sp. — One or two leaflets are clearly 

 comparable with those of the genus Gleditschia to which they are 

 referred under the name of G. donensis. 



The genus is at present represented in North America by two 

 species ('02, 76) of which the common three-thorned acacia, G. 

 triacanthos, seems to be more nearly related to the fossil, antl 

 presents the closer resemblance with respect to geographical loca- 

 tion. 



Madura aurantiaca Nutt. — One imperfect leaf is referable to 

 the osage orange. Although not now growing in the same region,. 



