POTTIA. 173 



mouth, after the fall of the lid. According to Venturi the var. cornea, usually attached 

 to the present plant, properly belongs, for the same reasons, to P. Starkeaka ; but 

 specimens of that var. from the herbarium of G. H. K. Thwaites, which I have no 

 doubt are genuine, have the spores with the fine, acute papillae of P. mmutula, and I 

 have little doubt that Wilson is quite right in considering both species to possess 

 analogous varieties, which are, as he says, very difficult to separate, but which may 

 be known by the difference in their spores. They do not, however, appear to be of 

 great importance. 



P. minntula will hardly be mistaken for any other species except P. Starkeana, 

 on account of its minuteness ; it is most like P. recta, but the deciduous lid and wide- 

 mouthed capsule at once distinguish it. 



9. Pottia Starkeana CM. (Weisia Starkeana Hedw.) 



(Tab. XXVI. G.). 



Very small, crowded, pale green. Stem very short, leaves 

 oblong-lanceolate or very broadly-ovate, variable in form, short, 

 acute, margin strongly revolute, nerve reddish, excurrent in a 

 cuspidate point ; cells above rather small, rounded-hexagonal, 

 rather incrassate, obscure, minutely and densely papillose. 

 Perichaetial bracts hardly distinct. Seta short, capsule small, 

 oval or shortly oblong, dark brown, shining, not wide-mouthed ; 

 calyptra rough; lid conical, obtuse. Peristome teeth variable, 

 more or less truncate and imperfect , of 2-4 articulations, linear, 

 flat, papillose, yellowish. Paroicous. Spores coarsely and 

 obtusely tuberculate. 



Var ./S. brachyodus Wils. (Var. /?. affinis Braithw., Br. M. 

 FL). Peristome teeth very short, truncate. 



Hab. Fallow fields and bare ground ; not common. The var. j8 less frequent. 

 Fr. winter and early spring. 



Although this is probably distinct from the last species the points of difference 

 are not numerous ; the capsule is usually more or less narrowed at the mouth, or the 

 mouth may be equal in width to the rest of the capsule, which, however, is not 

 urceolate, nor truncate as it sometimes is in that. The peristome is always present, 

 though sometimes very rudimentary ; and the spores, "resembling in miniature bags 

 filled with apples" as Venturi describes them, and translucent instead of being 

 rendered opaque, as in the other species, by densely crowded minute papillae, afford a 

 good and easily observed distinction. 



10. Pottia csespitosa C. M. (Weisia csespitosa Bruch.) 



(Tab. XXVI. I.). 



In small tufts, short, bright yellowish green, stems usually 

 branched at the base. Leaves small, ovate or oblong-lanceolate, 

 acute, margin plane, nerve excurrent in a very short green 

 mucro ; cells above very small, incrassate, irregularly hexagonal, 

 rough at the back with dense, obtuse papillae. Perichsetial bracts 

 distinct, erect and sheathing. Seta pale yellow ; calyptra smooth ; 



