Tempskya Whitei sp. nov. 

 Plates XXXVII, XXXYIII 



Description. — Polystelic filicineaii stems of large size. The steles 

 nTimerous and small, anastomosing and giving rise to numerous petiolar 

 strands. Entirely invested with a great mass of branching adventitious 

 roots. 



The latter are of various sizes and show a central axial vascular strand 

 surrounded by a decayed zone representing phloem and this in turn 

 surrounded by a sclerenchymatous zone. These roots are poorly pre- 

 served and it has been impossible to decide whether they are diarch as 

 Seward has described them for Tempshya ScJiimperi from the English 

 Wealden, or pentarch or hexarch as was asserted by Solms-Laubach. 

 One of the best-preserved roots is shown in the exact center of the micro- 

 photograph, reproduced on pi. xxxviii, fig. 1, which shows portions 

 of 2 steles, the lower of which is in the act of forking, while the periphery 

 of a larger stele is shown at the left side above. PI. xxxvii, fig, 2, 

 shows a transverse section entirely across a small specimen and fig. 1 

 on the same plate shows a longitudinal section which cuts across several 

 steles. 



It has not been possible to secure sections and properly study these 

 singular fossils in time to include the results in the present publication; 

 further characterization and histological description, together with a 

 discussion of their botanical affinity, are reserved for a special contribu- 

 tion. For the purposes of the present work they are included with a query 

 in the order Mamttiales, using that term in a broad sense so as to in- 

 clude the Paleozoic Psaroniege. 



As they appear to be specifically distinct from the numerous described 

 European forms they have been named as a slight token of esteem in 

 honor of Mr. David White of the II. S. Geological Survey. 



These remains bear a superficial resemblance to palm wood, in fact 

 they were, in the case of the English species, originally referred to 

 Palmacites and to Endogenites, both properly appellative of fossil palm 

 wood. In the Potomac area fragments of these trunks are often of con- 



