284 THE POTOMAC OE YOUNGEE MESOZOIC FLOEA. 



Flora der bohm. Kreideform., PI. I, Fig. 18). Conospermltes hakecefoUus 

 (Fig. 11 of the same plate) has a nervation similar to that of the Potomac 

 plant. 



PrOTE/EPHYLLUM, sp. '? 

 Plate CXXXIX, Fig. 2. 



This fossil is too fragmentary to justify an attempt to determine its 

 species. It forms the upper part of an elliptical leaf, most probably has a 

 midnerve which towards the summit splits up into branches. These are 

 slender and are sent off obliquely ; they subdivide irregularly into second- 

 ary branches, wliich anastomose irregularly to form large lax meshes. It 

 may be compared with I'rotea fflahra Thunb. It belongs to the elongate 

 section of I'roteiaphyllum. 



Locality : Fisliing hut above Dutch Gap Canal. 



PROTE.liPHYLLUM OBLONGIFOLIUM, &}). UOV. 

 Plate CXXXIX, Fig. 5; Phitc CXL, Figa. 1, 2. 



Leaf rather large, spatulate, oblong or oblong-elliptical, narrowed 

 very gradually below into the i)etiole ; summit not seen ; midnerve stout, 

 and continuing- to near tlie tip of tlie leaf; secondary nerves very slender, 

 leaving the midrib at a more or less acute angle, and arching around in an 

 irregularly flexuous manner to miite with those of the same order next 

 above, sending off branches obliipiely, mainl}- on the outer side, wliich 

 pursue a flexuous course parallel to the margin of the leaf, finally dis- 

 solving into smaller branches ; the lateral nerves anastomose into large, 

 irregular meshes, made up of subordinate meshes, the minor branches of the 

 lateral nerves, which meet under large angles, forming a net-work that is 

 very irregular; leaf-substance moderately thick; the ultimate reticulation 

 strong and fern-like. 



Locality : Fredericksburg. 



Leaves of this character are not unconmion at Fredericksburg. The 

 nervation is very lax, irregular, and archaic in type. The leaves are 

 always quite fragmentary, but so many specimens are found giving all 

 parts of the leaf, that a quite reliable restoration can be indicated. In PI. 

 CXL, Fig. 2, I give a full-size restoration of the leaf of the largest dimeu- 



