Maryland Geological Survey 409 



Description. — Leaves long and slender, .5 to 1.0 mm. in width, full 

 length not seen, at least several centimeters, much crowded, seen to be 

 in bundles where the preservation is fairly good. 



This is clearly distinct from the preceding species and less common. 

 It is not fully characterized because of the poorness of preservation as 

 evinced by the fact that the leaves are detached in a majority of the 

 specimens collected. The forms which were the basis for Laricopsis 

 longifolia Fontaine have been united with this species since they are 

 indistinguishable and probably identical in character. 



This species occurs at the oldest and youngest horizons in the Virginia 

 Potomac and it has also been recorded from the Kootanie formation of 

 Montana. The fragment from the Trinity beds of Texas which Professor 

 Fontaine identifies with such certainty is, in the writer^s judgment, 

 absolutely nntrustworthy. 



Occurrence. — Patusent Formation". Dutch Gap and immediate 

 vicinity, Virginia. Patapsco Formation. Brooke, Virginia. 



Collection. — U. S. j^ational Museum. 



Genus LARICOPSIS Fontaine 

 [Mon. U. S. Geol. Survey, vol. xv, 1890, p. 232] 



This genus received the following diagnosis by its describer: 

 " Trees or shrubs, with the penultimate twigs sending off alternately 

 in the same plane ultimate branches; leaves thin, narrow, and thread- 

 like, attached by the entire base either in bundles at the same point 

 on the stem or scattered singly on its surface, both on the same stem, 

 very deciduous, the leaf-bundles leaving small scars. Nerves not made 

 out with certainty, but apparently one for each leaf. 



" This genus is nearer to Larix than to any other known plant, and the 

 the resemblance is sufficiently great to render it possible that it may be 

 the ancestor of this genus. It should be noted that the young shoots 

 of Larix often have the leaves scattered singly as they occur in this 

 genus, and it is probable that the immature portions of Larix approach 

 the ancestral forms more nearly than the mature portions do. In these 



