OF WESTERN PENNSYLVANIA 1(K> 



or less revolute ; costa strong, reaching the apex or extending 

 into the apiculation ; upper leaf-cells opaque, incrassate, 

 papillose, from rounded to hexagonal or quadrate, towards the 

 base of the leaf becoming elongate, thin-walled and hyaline: 

 seta erect, 6-8 mm. high, sub-lustrous, sinistrorse, castaneous ; 

 capsule dark-castaneous, oblong, 12-15 mm. long; peristome- 

 teeth yellow, slender, divided almost to the base into two 

 slender, minutely-papillose prongs; annulus distinct, revolu- 

 ble ; operculum bluntly and obliquely conic-rostrate ; exothecial 

 cells brownish-incrassate, rectangular or oblong-hexagonal, im- 

 mediately below the annulus being smaller and incrassate; 

 spores smoothish, yellowish, .012-.015 mm., mature in spring. 



On sandy soil, rocks, etc.. mainly confined to the drainage- 

 system of the Ohio River. Not rare in our region. 



Crawford : Linesville, May 12, 1908. O. E. J. (Fig- 



ured). 



Favette : Along river-bank at Ohio Pvle, Septem- 



ber 1-3, 1907. O. E. J. and'G. K. J. 



McKean : Near Bradford. December 15, 1894. D. 



A. B. 



12. TORTi'LA Hedwig. 



Autoicous or dioicous, rarely synoicous or polyoicous : 

 small to robust, in green to brown tufts or cushions : stems 

 mostly with a central strand, below brownish- or red-radicu- 

 lose, simple or branched ; leaves mostly larger at the ends of 

 the shoots, often appearing rosette-like, when dry not crispate 

 but somewhat twisted and contorted, when moist erect-spread- 

 ing, mostly keeled, obovate or spatulate. rounded at the apex 

 or rarely short-acute, commonly bordered, usually entire ; costa 

 strong, often cylindric, often mucronate-excurrent or, more 

 commonly, excurrent into a hyaline hair-like awn ; upper leaf- 

 cells rounded-hexagonal, loose, chlorophyllose, papillose, grad- 

 ing below into the rectangular to elongate hyaline basal cells : 

 seta long, erect ; capsule erect, cylindric, symmetric, short- 

 necked, straight or sometimes slightly arcuate : annulus pres- 

 ent ; peristome single, rarely none, basal membrane low to high, 

 teeth 32, filiform, equally spaced, mostly once to twice dex- 

 trorsely wound, papillose and transversely striate, articulate ; 

 operculum conic, obliquely rostrate ; calyptra cucullate, reach- 

 ing to the middle of the urn ; spores small. 



A large genus of 202 species, widely distributed in the 

 temperate regions; 40 species occurring in North America; 

 only 1 species thus far reported in our region. 



Key to the Species. 



a. Small; leaves when dry contorted and twisted: basal membrane 

 low. b. 



