WHITE.] NOTES ON" CHARACTERISTIC SPECIES. 883 



Sl'HENOPTERlS PILOSA Dn. 



Tho specimens, including' the types, from the upper portion of the 

 Pottsville in Washington County, Arkansas, described by Les(|uereux' 

 as Sj)henopterls communis^ appear to present the identical specific 

 characters seen in examples of Sphenopteris pilosa from the so-called 

 middle Devonian beds at St. John. New Brunswick. In the Sewanee 

 zone, which includes the Arkansas beds, of which the species is 

 characteristic, we find it associated, as at St, John, with Pecopjteris 

 serrulata. The specimens from the Southern Anthracite field are 

 found near the supposed horizons of Lykens coals No. 2 or 3, at about 

 465 feet below the Twin coal, iti the gap at Pottsville. 



Aloiopteris georgiana (Lx.). 



The material described b}^ Lesquereux as Pecopteris georgiana" is 

 generically identical with the Aloiopteris Sternhergii^ A. Witislovii, and 

 A. e/'osa of the Productive Coal Measures. The species is notable for 

 the great length and proportionate narrowness of the rather distant 

 ultimate pinna?. The pinnules are nearly always at least tridentate, 

 the primary nerve forking below the middle, and once or twice again 

 in the upper part of the pinnule. The species which is, 1 believe, the 

 antecedent representative of this group in our American Carbon- 

 iferous is readily distinguished from A. Winslovii by its narrower 

 ultimate pinnae, the small pinnules, and the coriaceous texture. The 

 pinnules are proportionately a little farther distant, narrower, and 

 distinctly curved, the teeth sharp and directed forward, the nerves 

 curved and strong. Compared with A. Sternhergii^ the Georgia species 

 is much more cristate, the teeth more acute, the nerves stronger, more 

 open, and more upturned. The normal type is apparently character- 

 istic of the Mariopteris pottsvillea zone in the Lookout formation in 

 northwestern Georgia. The specimens in hand are from the roof of 

 Lykens coal No. 4, at the Lincoln colliery. 



Oligocarpia alabamensis Lx. 



Specimens from the Lincoln colliery agree in all respects with 

 typical material from Helena, Alabama, the original locality of the spe- 

 cies. The plant appears to be, on the whole, characteristic of the basal 

 portion of the Sewanee zone, though it may be found in the upper 

 part of the Marioj)terls potUtrUlea zone. 



Pecopteris serrulata Hartt. 



The representatives of this species in the Pottsville formation appear 

 to be in all respects in agreement with those from the type locality at 



1 Coal Flora, Vol. Ill, p. 762, pi. xeiv, figs. 1 and la. 

 2Ibid., p. 759, pi. xcviil, figs. 6 and 6a. 



