"7 



is unique in showing a complete, and what appears to be a fruiting 

 plant. Four floating leaves, three of which are nearly perfect 

 are clearly made out, as well as 14 thread-like divisions of the 

 submerged leaves with their appendages. Several of these dis- 

 sected submerged leaves appear to be complete and are 2.5 centi- 

 meters in length. Immediately beneath the lowermost and in- 

 complete floating leaf are two small sub-spherical bodies about 

 1.25 millimeters in diameter, and these appear to be in organic 

 union with the submerged leaves at their base and to represent 

 sporocarps. These are brownish carbonaceous and of con- 

 siderable consistency so that when the plant was buried and 

 flattened in the mud the floating leaf was pressed over them, and 

 when the clay was split the leaf film over them flaked off. Im- 

 mediately beside these objects, which are interpreted as sporo- 

 carps, is a similar impression in the clay without any carbonaceous 

 residue which might represent a third sporocarp. 



There can not be the slighest doubt regarding the botanical 

 affinity of this species, and although it is not possible to verify 

 the interpretation of the sporocarps, they appear very con- 

 vincing. In the Wind River basin this species is found on the 

 same slabs with the fruits of Sparganium and other representa- 

 tives of a lake side or slack stream vegetation. In Tennessee it 

 is associated with a large and varied costal and lagoon border 

 flora. 



Occurrence: Bridger (?) Tipperary, Fremont County, Wyo- 

 ming; Clover Creek, Hardeman County and Mandy, Madison 

 County, Tennessee. 



Salvinia preauriculata is so named because of its great similarity 

 to the existing Salvinia aunculata Aublet, which ranges from 

 Cuba and Central America to Paraguay'. Among the described 

 fossil species it is closest to Salvinia Zeilleri Fritel. The Wilcox 

 beds in which it is found are correlated with Ypresian stage of 

 the Eocene. The Wyoming occurrence, less certainly correlated , 

 is somewhat younger and may belong in the Lutetian stage of 

 the middle Eocene. If this is correct it would tend to indicate 

 that this species had spread northward to Wyoming from 

 Equatorial America during Eocene time. 



The still existing species of Salvinia also number a dozen or 

 more and they occur chiefly in the equatorial regions of both 

 hemispheres, and are especially abundant in South America. 



