324 A MANUAL OF MOSSES 



above when dry ; capsule yellowish, about 2 mm. long, cylindric 

 from a tapering- neck, inclined, arcuate, smooth, but when dry 

 and empty somewhat striate ; lid conic, acuminate to sub- 

 rostrate, about one-half as long as the urn ; peristome-teeth 

 bright orange at base, pale above, lance-subulate, confluent at 

 base, closely trabeculate, the dorsal lamellae finely cross- 

 striolate; segments slender, about as long as the teeth, nar- 

 rowly carinately gaping, the basal membrane about one-third 

 as high, the cilia very slender, about as long as the segments, 

 nodose, usually 3 in number ; exothecial cells moderately in- 



J * 



crassate, small and quadrate at rim, larger and oblong-rec- 

 tangular to rounded-hexagonal below; annulus large, re- 

 voluble, 2-seriate ; spores pale yellowish, smooth, rather thin- 

 walled, .006-,010 mm., mature in mid-summer. 



On humus, rocks, rotten logs, etc., in woods ; Europe, 

 Asia, northern Africa, and from southern Canada to Alabama 

 and from Alaska to Oregon. Probably more common in our 

 region than the localities here enumerated would indicate. 



Allegheny : Panther Hollow, Schenley Park, Pitts- 

 burgh, November 25, 1905, and \Yildwood 

 Road Hollow, Tune 11, 1908. (Figured). 

 O. E. J. ; Wildwood Road Hollow, No- 

 vember 19, 1908. O. E. T. and G. K. T- 

 Crawford : Linesville, May 12. 1908. O. E. J. 



Westmoreland : "Shades," near Blackburn, June 13, 1908. 



O. E. J. 



McKean : Manila Brook, Bradford, October 22 and 



November 16, 1896. D. A. B. 



4. Plagiothecium denticulatum [Linnaeus] Bryologia Europaea. 



(Hypiuun denticulatum Linnaeus). 

 (Plate XLVIII) 



Variable, in flattened tufts of a pale and lustrous green, 

 moderately robust, the more or less ascending and elongate 

 branches complanate ; leaves rather close, complanate and sub- 

 distichous, rather spreading, when dry little changed, glossy, 

 2-3 mm. long, sub-concave, oval to lance-oblong, shortly and 

 sometimes almost apiculately acute, usually slightly denticu- 

 late at the apex, the lower margins entire and often narrowly 

 recurved, the base narrowed to a rather w r ide and strongly 

 decurrent insertion ; costa thin, variable, usually short and 

 double, sometimes forked and reaching almost to the middle, 

 sometimes none; median leaf-cells rhomboid-hexagonal, rather 

 large, about 10-15:1, about .010-.015 mm. wide, thin-walled, 

 chlorophyllose, gradually becoming laxer, pellucid, and more 

 or less rectangular at base, the alar more hyaline, sub-rec- 

 tangular, sub-inflated, and still somewhat larger but not form- 



