Ig8 THE FLOEA OF THE DAKOTA GROUf. 



are often divided into tertiaries and quaternaries. The greatest difference, 

 however, niav he seen in the size of the pelta. A numher ^)f specimens of 

 P. Sternherffd more recently received, one of which is tigin-ed (PL XLII, 

 Fig. 1), have a narrow pelta, or rather a basal border, entered by one or two 

 basilar nerves which emerge at right angles from the base of the lui(h-il), 

 but do n(»t diverge downward into it. In P. Lecoutcanum as in P. pnesiaiis 

 the pelta is an enlarged part of the leaf analogous to the stipular append- 

 ages wliich remain attached to the base of the leaves of some species of 

 Platanus, as P. basilohata Ward, of the Laramie. 



Habitat: Ellsworth County, Kansas. No. 784 of the museum of the 

 Universit)- of Kansas; E. P. West, collector. 



Protophtllum prjestans, sp. nov. 

 PI. XLI, Figs. 2, 3; PI. XLII, Figs. 3, 4. 



Leaves large, membranous, long petioled, ovate, obtusely pointed, 

 rotmded at base into a broad peltate auricle covering the top of the petiole, 

 dentate on the borders except at the base of the auricle; nervation irregu- 

 larly palmately triiid ; primary basilar nerves open, nearly at riglit angles, 

 alternate ; lower primaries, tlu-ee pairs, curved downward into the auricle, 

 branching and anastomosing near the borders, craspedodrome in their divis- 

 ion; secondaries, seven or eight pairs, oblique, alternate or opposite, all fork- 

 ing one to three times from above the middle; divisions craspedodrome; ner- 

 villes strong, at right angles to the nerves, distant, rarely simple, mostly 

 forking at the middle. 



This fine species differs from its congener tirst by its somewhat thin 

 but hard, solid membranous texture, wliich renders its surface apparently 

 rough. Of the four leaves tigured, the largest, fully developed, is 20'''" long, 

 including the basilar, round pelta, and I.'")""' broad at the middle. The 

 smaller leaf, which is preserved entire (PI. XLII, Fig. 3), appears broadly, 

 angularh- pointed, and from PI. XLI, Fig. 3, the auricle, wliich in Fig. 2 is 

 parth' lacerated, is seen to be rounded and traversed from its margin around 

 tlie petiole to the borders by three pairs of primary Ijasilar nerves curving 

 downward. Its petiole is preserved entire and is 5°'" long and slightly 

 inflated at its point of attachment. Fig. 4 of PI. XLII is a fragment of a ' 

 very small leaf having the character of the species especially distinct in its 

 texture, the lower secondaries being arched downward. PI. XLI, Fig-. 3, 

 has the borders reflexed or immersed in the stone, and the secondaries, 

 therefore, are not seen in their whole length. 



