DESCRIPTION OF SPECIES. 61 



aries 6-10 pairs, oblique, parallel, equidistant, the lower opposite and 

 suprabasilar ; nervilles distinct at right angles; petiole slender, 10-18""" 

 long, stipidate at base. 



Habitat : Ellsworth County, Kansas. All the specimens numbered 

 below belong to the museum of the University of Kansas. Collected by E. 

 P. West. 



1. Betulites Westii var. subintegkifolius.' 

 PI. IV, Figs. 1-4. 



Leaves broadly ovate or oval, obtuse; truncate or subcordate at base; 

 borders nearly entire, minutely punctulate by tlie points of the extremities 

 of the secondaries entering the bordei's ; secondaries distnut, six pairs at an 

 open angle of divergence of 45° to 50°. Nos. 302, 313, 375, and 378 of 

 the collection. 



2. Betulites Westii var. obtusus. 

 PI. IV, Figs. 5-8. 



Leaves oblong-oval, rounded at apex, sul)truiicate at base; minutely 

 denticulate; secondaries of the same character as in the preceding. Nos. 

 235, 241, 260, and 263 of the collection. 



3. Betulites Westii var. latifolius. 

 PI. IV, Figs. 9-11. 



Leaves larger, 4-6"'" long, ovate, blunt-pointed, distinctly denticulate, 

 siibtruncate at base. Nos. 268, 261), and 276 of the collection. 



•1. Betulites Westii var. rotundatus. 

 PI. IV, Figs. 12-16. 



Leaves small, 1.5*^° to 3*"" in diameter both ways, or sometimes slightly 

 broader than long, minutely denticulate. Nos. 246, 344, 351, 380, and 397 

 of the collection. 



5. Betulites Westii var. oblongus. 

 PI. IV, Figs. 17-19. 



Leaves small, of same size as in the preceding variety, oljlong-ovate, 

 obtuse, subtruncate at base, denticulate. Nos. 281, 296, and 328 of the 

 collection. 



' Prof. Lesquereux gave all the varieties of this species the femiuiue termination (subintegrifolia, 

 etc.), as if treating of Betula. I have taken the liberty to change this to the masculine form to agree 

 with Betulites.— F. H. K. 



