POLYTHICH1EI. 213 



dichotomous ; leaves ligulato-lanceolate ; margin undulated, 

 sharply toothed ; sporangium cylindrical, curved ; lid with 

 a long curved beak. Hook. $ Wils. i. x. ; Eng. Bot. t. 1220.; 

 (Plate 19, fig. 4) ; Moug. fy Nest. n. 131. 



In woods, on shady banks, etc. Common. Bearing fruit 

 in winter. 



Forming broad patches; margin of leaves thickened, and 

 set with double teeth ; nerve with a few narrow plaits ; leaf- 

 cells oblong below, subrotund or subquadrate above; spo- 

 rangia sometimes binate; lid almost as long as the sporangium. 

 Resembling in habit Mnium undulatum. 



2. A. angustatum, Br. ty Schimp. ; dioicous ; stem shorter ; 

 leaves narrower, more densely reticulate, less hispid beneath ; 

 lamellae numerous ; sporangium narrow. Moug. fy Nest. n. 

 932. 



On sandy ground. Hurst Pierpoint. Mr. Mitten. Schim- 

 per pronounces Mr. Mitten's plants, though barren, to be 

 identical with the Continental species. It is a smaller and 

 more delicate species, with shorter spines, and far smaller leaf- 

 cells. 



3. A. tenellum, Br. fy Schimp. ; dioicous ; stem short, sim- 

 ple; leaves oblongo-lanceolate, scarcely undulated, even be- 

 neath ; margin toothed beyond the middle ; nerve slightly 

 lamellate ; sporangium subcernuous, obovate or oblong ; veil 

 obscurely hairy above; peristome large. Br. Eur. t. 412. ; 

 (Moug. tyNest. n. 1018). 



On dried muddy places or clay. W. Wilson. Bearing 

 fruit in autumn. 



The very short stem, short sporangium, and other points, 

 easily distinguish this species. 



