906 FLORAL ZONES OF THE POTTSVILLE FORMATION. 



prevailinj4"ly small, not over 13 mm. long, unci narrow, though the 

 species soon assumed its normal proportions in the Clark and Quinni- 

 mont divisions of the Pottsville in the central Appalachian region, and 

 near the horizons of the Lvkens coal No 4 and the lower Lykens coals 

 of the Southern Anthracite field. Occasionally larger or longer leaves 

 occur locally in the Lo\ver Lykens division; but in the Sewanee-Sewell 

 zone, or I'pper Lykens division, a larger form is somewhat characteris- 

 tic, while in the upper part of the series, at certain points in the 

 Southern States, and in the roof of Lykens coal No. 2, a very much 

 elongated slender form is found to prevail, almost if not quite exclu- 

 sively, locally. It is also possible that the large, arcuate leaves which 

 occur near Birmingham, Alal)ama, and at the Kemble drift and Koh- 

 lers Gap, are hardly specifically separable from the species in hand, 

 notwithstanding their local abundance and exclusiveness. 



The characters of the bases and petioles of these leaves are shown 

 in PI. CXC, Fig. 9. Typical examples are illustrated from the 

 Lykens coal No. 5 in PI. CXC, Figs. 10 and 11. The specimen seen 

 in Fig. 10 is below the average in size. As will be observed on an 

 inspection of the drawings, the mode of origin of the nerve fascicles, 

 the slightly ribbed character of the leaf, its dense fibrous texture, the 

 teeth, in which the nerves of each fascicle appear to be somewhat con- 

 nivent, and the nature of the petiole, all indicate its common generic 

 relation to Whittleseya inicrophylla and W. elegans. Owing to the 

 thickness and inward inclination of the teeth, the latter are often 

 obscured by imbrication or superposition. Not infrequenth% how- 

 ever, they are spread out erect, when the clearness of the dentation, 

 the vascular system, and the slightly cuneate outline show their con- 

 generic relation to the species considered in the preceding sections, 

 some of the cuneate forms thus approaching the IT" mlcroj^hyUa. 

 R«Mnark should be made of the presence, about 470 feet below the 

 Buck ^Mountain coal, of a straight, normally cuneate-linear form 

 attaining a length of 35 nnn. and a width of 6 mm. 



As with the other species of the gemis, none of the leaves of 117///- 

 tJeseya CanijjhtUl have yet been seen with absolute certainty to be 

 attached to any branch or axis, though they are sometimes found in 

 large num))ers matted together, their bases o])li([uely converging 

 toward a conuuon axis. 1 suspeet the fruits of the plant to be refer- 

 able to RliahdocarpOH. 



Wli'iffhxt'tjti C(iii,j)l>tlJl^ is at once distinguished by its lini^ar fonu 

 and small siz(> from aU the species of the genus yet descril)ed. 



The species occurs at nearly all localities of the Pottsville formation 

 in horizons below the Fayette sandstone of Virginia, the Conoquen- 



1 The spcc-it's is named in honor of my esteemed colleague, Mr. M. R. CiimpV)ell, geologist in charge 

 of theareal cartography of the Centnil Apf>alachian coal fields, to whom I nni greatly iiidt'bte<l for 

 abundant assistance in the collection of fossil material from all possible luculities in that region as 

 well as for valuable stratigraiihic data. 



