372 



MUSCI. 



complete, and would hence be a good and firm character. In 

 Hypnoideae, Leskia, Hookeria, Hypnum, etc., it is likewise 

 complete. 



In all cases, both peristomes originate from the inner theca, 

 but the inner one is a continuation of the same. No value is 

 to be attached to the point of exertion of the outer peris- 

 tome ; hence Entosthodon is not a distinct genus, or rather it 

 is not made so by this character. So constant is this latter 

 fact, that all have erred in asserting that Diphyscium has no 

 outer peristome, whatever the nature of the plicate membrane 

 may be, it is certainly analagous to an outer peristome. 



The peristome Polytrichi has nothing analagous to that of 

 other mosses, it is a continuation of the outer membrane, and 

 presents no traces whatever of composition ; it is in addition, 

 liable to much greater irregularly as to number, than that of 

 any other. It is probably a modification of the annulug. 

 Bridel is mistaken in saying, that the epiphragma is seized by 

 the apices of the teeth of the peristome. It is on the con- 

 trary, as it were, split opposite each tooth which is imbedded 

 in its substance, when the membrane is contracted as it always 

 is by dryness. For further remarks. // ass. 3, n. 126. 



Bridels class Hypophyllocarpa, is altogether wrong, the seta 

 is in these exserted from the axils of the leaves, and not of the 

 accessory ones ; so is Sir W. Hooker, I think, in calling them 

 stipulae, with which bodies they have nothing more in common 

 than in being foliaceous. Leskia incompleta, and its fellow 

 have evidently the same relation to Leskia, which Brachyme- 

 nium has to Bryum, hence it must be separated. Taking the 

 composition of the feajale flower into consideration, no ter- 

 minal fruited moss ought to be associated with a truly lateral 

 fruited genus. This derives confirmation from the fact, that 

 the genera of pleurocarpi are very few, in comparison with 

 those of acrocarpi. In Bridels Bryol Univ. there are about 70 

 genera of the former class, and only 29 of the latter. Fissi- 

 dens is a strong exception, both sorts of exertion of the setae 

 being met with. 



