102 SYNOPSIS OF BRITISH MOSSES. 



Limestone walls. October — March. 



168. B. ambigua, B. and 8. Larger in all its parts 

 than last. L. ligulate, lanceolate, apex cucullate, 

 margin incurved. Caps, erect, cylindrical, lid rostrate. 

 Calyptra very short. Perist. teeth filiform, little 

 twisted, arcuato-incurved when dry. Dioicous. 



Walls and banks (marly). November, December. 



169. B. abides, Koch. St. as above. L. spreading, 

 narrowly lanceolate, acute, with a strong nerve. Caps, 

 elongate-cylindrical, inclined, lid conical, acutely ros- 

 trate. Perist. teeth scarcely twisted, when dry widely 

 spreading. Dioicous. 



Clay banks. Winter and spring, 



170. B. lamellata, Lindh. [Pottia cavifolia var. gra- 

 cilis, Bry. Brit. B. cavifolia, Schp. Syn.). St. very 

 short, caespitose, L. rather lax, erecto-patent, concave, 

 lower smaller, roundish oval, piliferous, upper larger, 

 oval, spathulate, nerve excurrent into mucro. Caps, 

 oblong, subcylindrical, striate when dry, on a long red 

 seta, lid with a long, rather oblique beak. Perist. that 

 of a true Tortula, but so fragile as to have escaped 

 notice, and always falling off with the operculum. 

 Monoicous. 



Banks and walls. February. 



Oxford (Boswell), Pontefract, Edinburgh (Nowell), 

 Aldrington (Davies), &c. 



Section 2. CJJNEIFOLIM. 

 L. broadly or spathulato-Ianceolate. 



171. B. atrovirens, Smith, Lindh, [Bidymodon ner- 

 vosus. Hook, and T. Besmatodon nervosus, Bry. Brit.] 

 St. 5 inch, densely caespitose, branched. L. spreading, 

 oval, spathulate or oblong, concave, margins revolute. 



