-,iRT. 13 TOSSTL NUTLETS OF THE GENUS LITHOSPERMUM BERRY 3 



The genus LithosperTmmh comprises about two score existing 

 species of annual or perennial herbs, widely scattered in prevailing 

 <dry soil habitats, mostly in the Northern Hemisphere, but sparingly 

 represented in South America and Africa. The four-parted ovary 

 ■develops into four or fewer hard nutlets of rather characteristic shape 

 and with smooth and polished or wrinkled and pitted bony coats. 



I have reproduced nutlets of several recent species for comparison 

 "with tllft fossils. The fossil variety rugosum is, in both size and 

 form, much like the nutlets of the existing Lithosyenruumh lineari- 

 foliwm Goldie, shown in side and inside view in Figures 15 and 16. 

 This is a wide-ranging North American form found in dry situations 

 from Manitoba to British Columbia and southward to Illinois, Texas, 

 and Arizona. The species Z. arvense Linnaeus has a similarly 

 roughened surface. 



The fossil var. glabrmn is approached by a considerable number of 

 existing species with hard, smooth surfaces. Of these I reproduce 

 two, namely, L. imderale and L. pilosum. (Figs. 17, 18, 19.) Both 

 approach glai>ru?n in size and form, but differ in their greater width 

 and larger hilum. 



I have seen nothing among the modern forms which closely resem- 

 bles the fossil var. aristatumi: Other species than those reproduced 

 would serve equally well for comparison and illustration, but I have 

 not been able to see fruits of all of the species. 



EXPLANATION OF PLATE 



J'iGS. 1-10. Lithospennum fosHlmm rugosum, new species. 

 1-6. Phillips County, Kans. 

 7-10. Kit Carson County, Colo. 

 11-13. Lithospermmn fossilium glahrum Berry, new species. 

 Phillips County, Kans. 

 14, Lithospermum fossilium aristatum Berry, new species. 

 Phillips County, Kans. 

 15, 16. Lithospermum linearifolium Goldie. 



15 from side. 



16 from inside. 



17. Lithospermum ruderale Linnaeus. 

 From side. 

 18, 19. Lithospermum pilosum NuttaU. 



18 from side. 



19 from outside. 



All enlarged three times. 



o 



