No. 471] 



CRETACEOUS PLANT REMAINS 



193 



good state of preservation especially when charred, or partially 

 charred. 



Sedioninf/ and Microscopic Examination of Specimen's. — In 

 the case of lignitic or charred vegetable remains it is necessary 

 for successful study to obtain very thin sections, on account of the 

 dark color and opacity of the fossilized tissues. By the use of 

 hydrofluoric acid for removing mineral matter and by embedding 

 in thickened celloidin, it was found possible to make sections 

 often of large area, as thin as 5 micra which proved admirable 

 for photomicrographic purposes. These sections were cleared 

 at once in benzole without previous staining, since the natural 

 dark color of the lignites was sufficiently pronounced to differ- 

 entiate the structures, even in very thin sections. In some cases 

 it was found necessary to reduce the natural dark hue of the prepa- 

 rations and chlorine water was useful for this purpose. The 

 sections were mounted in balsam on plate-glass slides and after 

 previous drying were subjected to pressure and high temperature 

 in the warm oven for the purpose of making them perfectly flat. 

 All the photomicrographs in the present article were made by 

 means of Zeiss lenses, except those showing surface features. 

 The latter were executed with the admirable Heliar lenses of the 

 Spencer Lens Co. Electric light was employed in all cases as the 

 illuminant. 



Descriptions of Spkcimkxs 



Cone Scales Commonly Referred fo Daiinnani. — Fossil cone 

 scales similar to ours were described and figured for the first time 

 by Professor Edward Hitchcock,^ in his account of the organic 

 remains found at Gay Head, Martha's Vineyard. They were not 

 named by him, but his figures and description leave little to be 

 desired. He says: "Figs. 4, and 5, represent difiVreiit individuals 

 of another variety of vegetable remains. .. .Tliese arc not inrre 

 impressions; but a scale of carbonaceous matter, mixed with 



amber, marks the spot where the vegetable was imprisoned It 



seems to me ver/ obvious that these remains must be the seed 

 vessels of some coniferous plants." 



> Final Rept. Geol. 



pi. 19, figs. 4, 5, 1841. 



