FOSSIL NUTLETS OF THE GENUS LITHOSPERMUM 



By Edward W. Berry 



Of the Johns Hopkins University, Baltimore, Maryland 



There are in the collections of the United States National Museum 

 some hundreds of silicified fruits collected by the late John B. 

 Hatcher from the Loup Fork formation in 1884 which have never 

 been identified or described. More recently similar material has 

 been sent in from the undifferentiated Tertiary of Kit Carson County 

 in eastern Colorado. 



Among these are numerous specimens representing a new species 

 belonging to Lithospermum, a genus belonging to the family 

 Boraginaceae and not hitherto known in the fossil state. These show 

 a wide range of variation, but after much deliberation I have con- 

 cluded that the best method of treatment would be to consider all 

 of them as varieties of a single botanical species which may be called 

 Lithospermum fossilium. 



The smallest and most abundant variety may be described first as : 



LITHOSPERMUM FOSSILIUM RUGOSUM, new variety 



Plate 1, Figures 1-10 



Nutlets relatively small, averaging about 3 millimeters in length, 

 2 millimeters in width, and 2.5 millimeters in thickness. They are 

 contracted upward to a distal cuspidate but rounded apex, and are 

 asymmetrically inflated, the outside being much more convex than 

 the inside, both the apex and hilum being nearly in the plane of 

 the less inflated inner side. On the inside a rounded keel extends 

 from the apex nearly or quite to the hilum. The hilum is large and 

 circular, from 0.5 to 1 millimeter in diameter. The surface is rugose 

 but varies from nearly smooth to an aerolation of well-marked ridges. 

 This variation in sculpture is not due to abrasion before or after 

 fossiiization, I am quite sure, since it would have been equally effec- 

 tive on the apical point or the delicate rim of the hilum, which is 

 not the case. 



Found in both Kansas (figs. 1-6) and Colorado (figs. 7-10). 



No. 2734.— PROCEEDINQS U. S. NATIONAL MUSEUM, VOL. 73. ART. 13 

 86418—28 1 



