OBSERVATIONS ON SOME -^ARINE HLAFTS 289 



crowded with this really strange form, is so massed as to make a 

 description of the species especially difficult, and may be somewhat 

 modified when isolated forms are procured enabling this to be done. 

 I know of no other fossil marine plant approaching this in form or 

 general appearance. 



Position and locality: Covering the surface of a certain bed of 

 hard limestone below the two nodular Stromatopora beds of the 

 upper part of the middle Devonian ("Cedar Valley"), at Bloody 

 Run, Floyd County, lotva, and so far as known restricted to this 

 horizon and locality. 



Now in the author's collection. 



Fruticristatum noraense. N. Sp. * 



vStem of this seaweed or "fucoid" small and slender; circular; 

 broadly to sharply curved or bent; solitary; gradually and grace- 

 fully tapering from the base; termination sharp to rounded; 

 generally from one-eighth to one-fourth inch in diameter near the 

 base; varying in length from <)ne and one half to six inches; surface 

 apparently smooth; known only in the form of casts. 



Position and locality : Occurs in considerable numbers m narrow 

 bands of crinoidal limestone at Nora Springs, Bumgardner's quarry, 

 at Rock Grove, at John Turner's quarry, Rockford, and other 

 localities in the north-central part of Iowa, in the central part of the 

 middle Devonian. , , 



Now in the author's collection. 



Fruticristatum pervetus. N. Sp. 



Stem compressed to sub-circular; strong and robust; quite 

 strongly curved; surface uneven, and not otherwise marked; 

 length unknown but apparently attaining six to eight inches; 

 sending out strong lateral branches at intervals of an inch and a 

 half; diameter six-eighth to three-fourths inch; root medium 

 large, flattened or Sub-circular, smooth or marked by elongated 

 elevations, sharply constricted above; known only in the form of 

 casts. 



Position and locality : Found associated almost everywhere with 

 F. noraese, and is quite abundant. 



Now in the author's collection. 



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