OF WESTERN PENNSYLVANIA 289 



2a. Hygrohypnum cugyrium variety mackayi (Schimper) 

 Brotherus. 



(Hypnutn engyriutii var. mackayi Schimper ; Hygrohypnum maC' 

 kayi Loeske; Hypnuin mackayi Breidler). 



(Plate XLI) 



Leaves about 1-1.5x0-6-0.7 mm., broadly oblong, distinct- 

 ly serrulate at apex, sub-clasping and auriculate at base, less 

 strongly falcate than in the species ; perichsetial leaves hyaline, 

 plicate, the inner reaching 3 mm. in length : seta about 2 cm. 

 long, castaneous, smooth, somewhat flexuous, dextrorse above ; 

 capsule with urn 2-2.5 mm. long; exothecial cells rounded- 

 hexagonal, somewhat incrassate-collenchymatous, rather uni- 

 formly seriate; peristome-teeth about as long as the slender 

 carinate segments, the basal membrane about two-fifths as 

 high ; spores minutely papillose, rather thin-walled, faintly 

 yellowish, about .024-.027 mm., mature in late spring or early 

 summer. 



On stones in streams in hilly or mountainous regions and 

 with about the same general distribution as the species. Rare 

 in our region. 



McKean : On stones in brook at head of Bennett 



Brook, Bradford, August 26, 1894, Novem- 

 ber 2, 1896, and July, 1897. (Figured), the 

 latter issued as Grout's North American 

 Afusci Pleurocarpi. No. 129. Also Lime- 

 stone Creek, Bradford, July 7, 1895. All 

 D. A. B. 



3. Hygrohypnum ochraceum (Turner) Brotherus. 



{Hypnum ochraceum Turner ; Amhlysteginm ochraceum- Lind- 

 berg: Limnobium ochraceum Bryologia Europsea). 

 (Plate XLI) 



Yellowish or rusty green, softly cespitose in wide tufts: 

 stems up to 8 or 9 cm. long, ascending or horizontally floating, 

 sparsely and irregularly pinnately branched, without rhizoids, 

 the stems and branches somewhat hooked at the apex, the 

 cortical cells of the stem very large and relatively thin-walled ; 

 leaves falcate-secund, concave, plicate, widely lance-oblong, 

 somewhat rounded at the base, the margins plane, entire ex- 

 cepting for slight serration at the rather widely sub-obtuse 

 apex; costa single or double, often reaching half the length of 

 the leaf; median leaf-cells linear--vermicular, about 8-14:1, fair- 

 ly thick-walled, usually rounded at the ends, the apical oval- 

 rhomboid and much shorter, the basal larger and towards the 

 angles of the leaf forming distinct auricles of enlarged, hyaline, 

 inflated, rectangular cells: perichaetial leaves ecostate, lance- 



