GRIMMIACE^.] 66 [Otthotrichitm. 



seldom exserted above the upper leaves ; the caps, is symmetric, erect, oval 

 or subcylindric, almost always striate with 8 or 16 vittae or bands, which 

 after sporing, produce on the ripe dry capsule as many ridges and furrows, 

 these bands or ribs consist of darker and larger cells than the intermediate 

 tissue, arranged in 2 5 vertical series, and their walls, especially the lateral, 

 much and often irregularly thickened. The peristome is very rarely wanting, 

 and is extremely variable, the teeth consist of 32 flat lanceolate processes, 

 generally united in pairs (geminate), or in fours (bigeminate), and are 

 covered with papillae, but sometimes with very minute sinuous lines, and 

 when dry are erect, spreading horizontally, or reflexed against the capsule ; 

 very often an endostome is also present in the form of 8 or 16 cilia, consisting 

 of i or 2 rows of cells, opposite to the ribs of caps, and therefore alternate 

 with the teeth ; too much value however must not be fixed upon them, as 

 they are sometimes imperfect or abortive. The calyptra is campanulate or 

 conical, longitudinally plicate, more or less covered with straight hair-like 

 processes, or sometimes quite smooth. 



A very important character has been discovered in the two forms of 

 stomata found on the lower part of the capsule, and applied by Lindberg in 

 1866 to divide the genus into two sections ; these are i. Superficial (termed 

 phaneropores by Milde, stomata normalia by De Notaris, stomata nuda by Venturi), 

 which are seated in the cuticle only, and the two stomatic cells are thus 

 naked and visible ; 2. Immersed (cryptopores of Milde, stomata sphincteriformia 

 of De Notaris, stomata periphrasta of Venturi), these are sunk in the capsule- 

 wall and the two stomatic cells more or less covered by a circle of projecting 

 cuticular cells. In order to obtain a proper knowledge of the form of the 

 capsule, it should be soaked in water for some hours, and to observe 

 the stomata the base of the caps, should be cut off, the fruit slit up 

 on one side, the spore sac removed, and the pericarp with the cuticular side 

 upward, spread out in water on a slide and covered with glass ; a power of 

 300 will be required. Dr. Carrington added largely to the knowledge of our 

 native species in the Phytologist for 1858, and Dr. Venturi, of Trient, who 

 has for years paid unremitting attention to the genus, first in Hedwigia for 

 1871 3, and recently in Parts 56 of Husnot's Muscologia gallica. has given 

 masterly descriptions of all the European species, which leave little to be 

 desired. 



CLAVIS TO THE SPECIES. 



Stomata superficial. 



Leaves obtuse, with plane margins. vbtitsifulium 



more or less acute, with recurved margins. 



Peristome simple. Shawii. 



Peristome and endostome present. 



Capsule without ridges. striatitm. 



with ridges and furrows. 



Autoicous, cilia 8. 



Capsule striate nearly all its length. 



Caps, short, brown ; calyptra yellow. rtipestrc. 



long, narrow, pale ; cal. pale greenish, affinc. 

 Capsule faintly striate at upper end. speciosum. 



Dioicous, cilia 16. Lycllii. 



