2l6 TORTULACE^. 



The only specimen I have seen of the plant described above as var. gracile is a 

 barren specimen of Mitten's from Weymouth. It differs so little from some forms of 

 Tr. crispulum, notably the vars. brevifolium and angustifolium B. & S. , that I cannot 

 think it worthy of specific rank. The leaves are frequently slightly cucullate, quite as 

 much so as in the above varieties, which together constitute the var. viridulum 

 (Bruch) (M. crispula var. viridula Braithw.); although often quite straight or only 

 exhibiting a very slight upward curve in the nerve. The fruiting characters certainly 

 have the appearance of greater weight, but the capsules in this group show a very 

 frequent tendency to become stunted (a small capsule is one of the characters of the 

 var. brevifolium B. & S. ), and the fruit as figured by Braithwaite has all the appear- 

 ance of a somewhat dwarfed and abnormal capsule ; and this is rather supported than 

 contradicted by the fact that the lid is exceptionally long in proportion, since it 

 frequently happens in stunted moss capsules that the lid retains its usual length. 



2. Trichostomum mutabile Bruch (Mollia brachydontia 

 Lindb., Braithw. Br. M. Fl.) (Tab. XXXI. J.). 



In its typical form this differs from T. crispulum in its leaves 

 tapering to an acute point with the margins hardly or not 

 incurved, the nerve straight, not upturned at point, excurrent in 

 a longer, distinct mucro, the hyaline basal cells more numerous 

 and wider, the margins generally slightly undulate. The leaves 

 also are usually more spreading at the top of the stem, often 

 slightly recurved in their upper part. The size of the leaf is very 

 variable, and the form of the apex is also subject to much 

 variation, from slender and tapering to rounded, wide, and some- 

 what obtuse ; and the margins may be slightly incurved. Seta 

 yellow. Capsule oval-oblong or narrowly elliptical, sometimes 

 slightly unequal ; peristome yellow, almost smooth, short, more or 

 less imperfect. 



Var. /3. httorale Dixon (Trichostomum littorale Mitt., Schp. 

 Syn. ; Mollia littoralis Braithw., Br. M. Fl.). Leaves wider and 

 shorter, more patulous and recurved above, oblong-Ungulate, 

 rounded and more or less obtuse at apex, margins plane or 

 slightly incurved at apex, distinctly denticulate at a short 

 distance above the base. 



Var. y. cophocarpum Schp. Taller, red below. Leaves 

 more erect, linear-lanceolate, longer, acuminate and acute. 

 Capsule short, oval, peristome rudimentary. 



_ Hab. Rocks and banks, chiefly near the sea. Frequent. Tne var. in 

 similar, more shaded situations ; frequent. The var. y rare. Fruit rare, spring. 



This species is subject to even greater variation than the last, and the slender- 

 leaved form is very different in appearance from the extreme form of typical var. 

 littorale, but I can see no adequate ground for giving the latter specific rank, seeing 

 that the fruiting characters appear to be identical with those of T. mutabile, while 

 intermediate forms of leaf-apex of every shade of obtuseness are found ; the 

 denticulate margin of the leaves below the middle is also sometimes to be found in the 



