500 INTRODUCTION TO CRYPTOGAMIC BOTANY. 



558. The pleurocarpous Fontinalei answer to Ripariei in 

 the acrocarpous series. They have the same floating habit, 

 but they are evidently connected with many pleurocarpous 

 mosses, as Gryphcea, Spiridens, &c. The peristome of the 

 common Fontinalis is a most elegant microscopic object, from 

 the beautiful cancellation of the inner teeth, and the cross 

 bars or trabecules, as they are called, of the outer teeth, which 

 are united above in pairs, and are slightly twisted when dry. 

 Dichelyma differs from Fontinalis in its dimidiate calyptra, 

 and its frequently exserted sporangia. These are mosses of the 

 northern hemisphere. No species appears in the Antarctic 

 Flora, or in that of New Zealand. The common Fontinalis 

 has received the specific name of antipyretica, because it is 

 used in Sweden to stuff the space between the chimney and 

 the walls to prevent fire, which it is said to do effectually from 

 its not being inflammable. Its triquetrous stems are very 

 curious, and the keeled leaves, clasping at the base, call to 

 mind those of Drepanophyllei, though they are quite destitute 

 of nerves. Sometimes the leaves are cloven along the keel, 

 when they resemble the oblongo-lanceolate leaves of F. 

 squamosa. 



5. Cryptotheciei, Br. & Sc. 



PlLOTRICHEI, Milll. 



Stems cylindrical ; leaves imbricated ; calyptra mitriform ; 

 peristome single or double. 



559. This, again, is a small tribe consisting of a few genera 

 only, and these probably ought to be reduced in number, as, 

 in many natural genera, species with a single and double 

 peristome cannot be properly separated from each other. Thus 

 Gryptotheca differs from Gryphcea only in the single peri- 

 stome. Esenbeckia differs principally in the plicate, serrated 

 leaves. Gryphcea differs from Meteorium in the small conical 

 calyptra and immersed sporangia. The habit of Meteorium, 

 moreover, as the name implies, is pensile ; while Pilotrichwrn 

 has a rigid erect habit. Several species of Meteorium and 

 Gryphcea are found in New Zealand, and other southern 

 regions. Gryphoia heteromcdla is a common British moss, 

 exhibiting very well the characters of the tribe. This some- 



