DESCRIPTION OF THE SPECIES. 227 



Locality : 72d mile-post, near Brooke. 



Only one specimen of this fossil was found. It seems to be the male 

 anient of some conifer, possibly of some one described under another 

 name. Fig. 7"* represents one of the scales flattened out ^ly pressure on 

 the surface of the clay. Fig-. T'' represents the shape of the enlarged scales 

 as they were attached to the axis. 



Ament of conifer, (/) sp. i 



Plate CXXXVI, Vig. 8. 



Fig. 8 represents small catkins, that occur rarely, grouped together in 

 large numbers on the surface of some portions of the clay at the 72d mile- 

 post. Where found they cover the surface confusedly, as if they had 

 floated in numbers on the surface of the water. They occur only in small 

 bits, none showing the entire length. They were linear in shape. No 

 conjecture can be made as to the species of tree from which tliey come. 



LEPTOSTROBUS Heer. 



"Strobile stipitate, ver}^ long, with scales that are loosel}' imbricated, 

 narrowed at base, and have the upper margin crenulate ; * * * leaves 

 needle-shaped, fasciculated on shortened branches." This is Heer's descrip- 

 tion of the genus formed to contain peculiar Jurassic plants from eastern 

 Siberia. He says of Lcptostrohus rigida^ that the leaves are 2°"" wide, very 

 long, with two very distinct nerves, which sometimes show between them- 

 selves some very fine striaj (see PI. VII, Fig. 11"). Some of the fragments 

 of leaves that he saw were 10.5"™ long with the ends not present. If we 

 modify Heer's description so as to make it read: leaves needle-shaped, very 

 long, 2""° and under in width, scattered on the larger or principal stems 

 and grouped in bundles on the ends of short twigs, attached directly to the 

 stems, nerves slender and parallel, we shall 1)e able to include in this genus 

 certain remarkable conifers found in the Potomac strata. These Potomac 

 fossils are a good deal like Schizolepis Fr. Braun, but the leaf of this lat- 

 ter had only one nerve. 



' Flor. Fobs. Arctica, vol. G, pt. 1, Nachtrilge zur. Jura-Flora Siberiens, p. 25. 



