OF WESTERN PENNSYLVANIA 187 



a. Upper leaf-cells .007 to .015 mm. in diameter; costa and lamellae 

 extending, over one-fourth to three-fifths of the width of upper 

 half of leaf. c. 



b. Lamellae 3-6 in number and 3-6 cells in height, covering 

 about Vs to */4 of the upper leaf-width. 



1. C. nndulata. 



b. Lamellae 5-7 in number and 4-7 cells in height, covering 

 about Yf, to y$ of the upper leaf-width. 



10. C. unditlata var. alle- 



glicniensis. 



c. Lamellae 5-8, 6-8 cells high, covering Y to Y 2 of upper leaf- 

 width. 2. C. angnstata. 

 c. Lamellae 6-8, 8-14 cells high, covering about l / 2 to % of upper 



leaf-width. 3. C. papillosa. 



c. Lamellae 7-12, 8-14 cells high, covering about 2 /$ to y$ of upper 

 leaf-width. 4. C. plurUameUata. 



1. Catharinaea undulata [Linnaeus] Weber and Mohr. 

 (Brynm undulatiun Linnaeus; Atrichum un-dulatum Beauvois). 



(Plate XXVI) 



Loosely cespitose, dull, dark green : stems erect, ranging 

 from 1.5-6 cm. long, usually about 3-4 cm., mostly simple, 

 more or less gray-radiculose below, arising from a rhizone- 

 like base ; lower leaves minute, increasing in size upwards, 

 the upper leaves lanceolate-lingulate, much crisped when dry, 

 transversely undulate when moist, sub-acute to obtuse, about 

 6-8 mm. long, 1 mm. wide, serrulate to the middle or slightly 

 below, the uppermost teeth double, strong, being inserted in 

 a border of 1-3 rows of brownish, pellucid to hyaline, incras- 

 sate, narrow cells ; the crests of the undulations on the back 

 of the leaf also often spinose in upper part of the leaf; leaf-cells 

 elongate-rectangular at base, reaching about .01 7 X -033 mm., 

 becoming quadrate towards leaf-middle, towards apex hexa- 

 gonal and somewhat longer transversely and about .017-.024 

 mm. ; costa strong, ending just below apex, sharply dorsally 

 toothed, ventrally with 3-6 longitudinal lamellae which each 

 consist of 3-6 rows of cells similar to those of the leaf-blade, 

 the costa and its lamellae covering rarely more than one-fourth 

 of the total leaf-width (in our region sometimes even nar- 

 rower) : seta erect, flexuose, somewhat sinistrorse, smooth, 

 lustrous castaneous, 2-5 cm. long; capsule lustrous, becom- 

 ing dull with age, castaneous, cylindrical, arcuate to almost 

 straight, inclined, smooth, about 4-5x1-1-3 mm.; peristome 

 single, the 32 teeth linear-lanceolate, obtuse, about 0.3 mm. 

 high, orange-pellucid along the median line, united in the 

 lower third into a reddish-orange basal membrane, the teeth 

 covered (especially along the margins) with a hyaline, densely 

 but minutely papillose layer which, during the winter, becomes 

 deciduous, thus leaving the teeth perfectly smooth ; spores 

 smooth, orange, spherical, about .016-.019 mm. in diameter; 

 mature in late fall, operculum conic, curved linear-rostrate, 



