UTICA SLATE AND HUDSON-RIVEE GROUP. 261 



FOSSIL PLANTS OF THE UTICA SLATE AND HUDSON-RIVER GROUP. 



We find in this group several well marked species of marine plants, with other forms 

 simulating, if not actually, organisms of this class. The prevailing forms are similar to those 

 of the preceding strata, but the same species have not been recognized. The nature of the 

 sediment, and the condition of the ocean bed, were favorable to the development and 

 growth of this kind of vegetation ; for we find, in almost every locality, evidences of its 

 existence. As our researches have been principally directed to the discovery of animal 

 fossils, little examination has been made in situations most favorable for the preservation 

 of these plants ; and we may anticipate a very large accession to the number of species, 

 when careful explorations are made. The species already obtained show a considerable 

 variety of form, and it is evident that we are but commencing our knowledge of the 

 ancient marine flora. 



The two following species appear to be quite new, and to require a generic designation. 



Genus S P H EN T H AL L US. 

 [Greek, tfiptiv, a wedge, and ^aXXog, a branch or frond ; in allusion to the form of the leaves.] 



Character. Plant consisting of a stem, with diverging wedge-form leaves, or of detached 

 leaves having this form. Leaves apparently succulent or thickened, and sometimes sub- 

 coriaceous. 



It will probably be found that plants of this character are restricted to Silurian, and 

 perhaps Lower Silurian strata. 



314. 1. SPHENOTHALLUS ANGUSTIFOLIUS (n. «p.). 



Pu LXVIII. Fig. I. 



The specimen is a fragment, consisting of a stipe or stem, to which are attached elongated 

 narrow cuneiform leaves. These leaves appear to proceed in tufts, and are accompanied 

 by other smaller and narrower ones about their base. The stem presents no distinct 

 markings, though there are several obscure impressions which may have been the point 

 of attachment for leaves. The leaves are obscurely striated, though nothing like a veined 

 structure can be distinguished. 



The fragment has much the appearance of the terminating portions of the Calamites; 

 and it is difficult to believe that it is not a land plant, though in a position so far below 

 where anything of the kind has heretofore been discovered. 



Position and locality. The specimen figured, with another obscure fragment, were 

 obtained from an authentic locality, between the village of Canajoharie, on the Mohawk, 

 and Schoharie village, by Mr. Lyman Wilder, of Hoosick falls.* 



• I am thus particula.' in stating the locality, and my authority for the specimens, though the succeeding species 

 serves to establish the fact of its occurrence in this position. 



