Maryland Geological Survey 455 



Cyperacites potomacensis sp. nov. 

 Plate LXXIX, Fig. G 



Description. — Plants of small size, with slender, somewhat flabellate, 

 linear leaves. Culm slender, apparently flat, preserved for a length of 

 2.2 cm. (apical part missing) and bearing 1.6 cm. from the base, a 

 single fruiting head, the subtending bract being apparently reduced to 

 a small scale. Head oblong conical, about 5 mm. in length and 2 mm. 

 in width as preserved with a short peduncle about 1 mm. in length. 

 Achenes relatively few in number, apparently angular, much flattened. 

 The associated leaves are flat and slender, about 1/3 of a millimeter 

 in width. 



This species is based upon the specimen figured and its counterpart, 

 comprising the culm with the attached fruits and the more or less 

 broken remains of four leaves, apparently belonging to the same indi- 

 vidual as does the culm. It was evidently a small and delicate form 

 and not a young plant since the achenes must have been nearly or quite 

 mature to have left such sharp impressions in the clay. The preserva- 

 tion is such that no details can be made out but it is clearly referable 

 to the sedges and might be matched by a number of modern species of 

 Garex. As previously mentioned it is of considerable interest in that 

 it furnishes conclusive evidence of the existence of this supposed modern 

 family of Monocotyledons at an age as remote as the late Lower Cre- 

 taceous and it is of further interest, even preserved as poorly as it is, 

 in representing a fruiting specimen of these comparatively rare types. 



Occurrence. — Patapsco Formation". Near Wellhams, Anne Arundel 

 County, Maryland. 



Collection. — Johns Hopkins University. 



