AKT.23 THE ESMEEALDA FOEMATION BEEEY 5 



The certain remains of sporocarps have not been detected because of 

 the poorness of preservation, but certain parts of the fossils distinctly 

 suggest that they represent microsporocarps since they show im- 

 pressions of small globular bodies that resemble microsporangia, 

 although they may be massulae. 



It is most unfortunate that this interesting form which looks so 

 convincing to the naked eye fails to fulfill its promise of detail when 

 magnified. I am quite sure that it is an Azolla^ and it is of especial 

 interest since no fossil species of this genus, except the remains of an 

 existing species in the European Pleistocene, have been known until 

 recently. Last year Reid and Chandler ^ described the very complete 

 remains of a species, Azolla prisccb, from the Oligocene of the Isle 

 of Wight, in which they were able to make out, most conclusively, 

 most of the details of organization. It was this discovery and the 

 resemblance of the Esmeralda fossils to the English material which 

 convinced me of the nature of the former. 



Occurrence. — Coal prospect 4 miles southeast of Morgan Ranch 

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



Holotijpe.—C2it. No. 37299, U.S.N.M. 



Order POLYPODIALES 



Genus DRYOPTERIS Adanson 



DRYOPTERIS OBSCURA (Knowlton) Berry 



GleicJienia (?) o'bscura Knowlton, U. S. Geol. Surv. 21st Ann. Rept., pt. 



2, p. 210, pi. 30, figs. 1-4, 1901. 

 Dryopteris (?) gleichenoides Knowlton, U. S. Geol. Surv. 21st Ann. Kept., 



pt. 2, p. 211, pi. 30, figs. 5-7. 



These two nominal species of ferns are clearly different parts of 

 the pinnae of a single botanical species. They are not represented 

 in the recent collections studied by me. In the absence of fruiting 

 characters the reference to Dryopteris is not conclusive, although 

 their form and venation suggest such a reference. They are cer- 

 tainly not related to Gleichenia aside from the improbability of the 

 occurrence of this genus in Nevada in Miocene time associated with 

 a flora such as that indicated by the other Esmeralda plants. 



8 Reid, E. M., and Chandler, M. E. J., The Bembridge flora, p. 40, figs. 2, 3. pi. 1. 

 figs. 14-24, 1926. 



