■10 PEOCEEDINGS OP THE NATIONAL MUSEUM vol.72. 



Marsh, Idaho,^ merely in its more truncate base, a feature of doubtful 

 value. Since, however, the numerous leaves of what has been con- 

 sidered by Knowlton ^ to be this species in the Latah formation of 

 Washington fail to show the basal features of this Esmeralda form^ 

 I have felt constrained to give it a varietal name. 



Occurrence. — Coal prospect 4 miles southeast of Morgan Ranch 

 and 15 miles west of Hawthorne, Mineral County, Nev. 



Eolotype.—GdX. No. 3Y303, U.S.N.M. 



Order RANALES 

 Family CERATOPHYLLACEAE 

 Genus CERATOPHYLLUM Linnaeus 



CERATOPHYLLUM FOSSILIUM, new species 

 Plate 1, figs. 2-4 



Nut or achene moderately compressed, elliptical in profile, highly 

 but variably spined over much of the surface. The style is per- 

 sistent and becomes a beak, which in one specimen is preserved for 

 a length of 5 millimeters. The margin is narrowly winged and bear& 

 a variable number of spines of various lengths; some mere mucro- 

 nate teeth, others long and slenderly incurved or recurved. The 

 basal spine on each side, usually termed spurs, are invariably present 

 and well developed and in instances are preserved for a length of 4 

 millimeters. Four specimens have been available for study, and 

 these are rather uniform in size and form but show considerable 

 variation in the degree of development of the marginal spines. The 

 average length of the four fruits is extremely close to 6 millimeters,, 

 and the maximum width ranges from 3.5 to 4 millimeters. The 

 fossil is thus well within the limits of size of the nuts of the existing 

 species. The beak, spurs, and those spines which are developed 

 beyond the tooth stage become exceedingly slender distad, and in 

 no case is it certain that their delicate tips have been fossilized. This 

 is all the more probable since in those existing species which are 

 spinose the beak and spurs are relatively longer than they are in the 

 fossil. Three of the four specimens are figured to show the varia- 

 tions exhibited. All three contain lignified portions of the original 

 fruit showing that is was decidedly resistant and that, allowing 

 for compression during fossilization, it has retained a thickness of 



9 Knowlton, F. H., The fossil plants of the Payette formation : U. S. Geol. Surv. 18tb 

 Ann. Kept., pt. 3, p. 728, pi. 101, figs. .3, 4 ; pi. 102, flgs. 1, 2, 1898. 



■^ Knowlton, F. H., Flora of the Latah formation of Spokane, Wash., and Coeur d'Alene,. 

 Idaho : U. S. Geol. Surv. Prof. Paper 140, p. 38, pi. 22, figs. 3, 4, 1926. 



