28 G Y M N O S T O M I. [ Schistostegn. 



naked; lid at length dividing into teeth-like processes? 

 Calyptra campanulate. (TAB. I.) 



We have never been so fortunate as to gather fresh specimens 

 of this curious genus ; and it is only upon the plants preserved in 

 the Herbaria of our friends and of ourselves, that we have been 

 able to make our observations. The result of these has been by 

 no means satisfactory in enabling us to verify those of Hedwig 

 and Mohr, relative to the splitting of the lid into segments. Our 

 drawing of this character is consequently taken from Hedwig, and 

 we have adopted the genus, relying wholly on Hedwig's character 

 combined with its peculiar habit, which at first sight approached 

 near to that of the distichous-leaved Dicrana ; and it is not im- 

 probable, that, mistaken for some of the small varieties of Dicra- 

 num bryoides, it may have escaped the notice of many Botanists in 

 Britain. 



We regret to be obliged to say that we have nothing important 

 to add to the result of our own investigations of this genus, since 

 the publication of the above remarks in our first edition of this 

 work. We have, indeed, examined many perfect specimens ; we 

 have carefully removed a lid from fully formed capsules, and we 

 have seen that this is plane, and formed of a distinctly cellular 

 texture ; the cellules radiating from the centre towards the circum- 

 ference, where they always become gradually larger ; but we have 

 not been so fortunate, even in capsules that have appeared to be 

 perfectly mature, as to see any splitting of the operculum, or any 

 division into laciniae. 



The Rev. Mr. Tozer, who has recently found this plant in con- 

 siderable plenty in Devonshire, has communicated the following 

 results of his observations to Dr. Greville : " The operculum I 

 examined, was irregularly circular, having two fissures at the 

 opposite extremities, and this being allowed to remain under the 

 microscope for a few hours, it separated into two parts. I en- 

 deavoured with a needle, of which the point was curved, to bring 

 the fragments within the field of view ; but, on being touched, they 

 split into many segments from the circumference to the centre." 



From these remarks it would appear that the operculum of 

 Schistostega, (though probably not in a state of nature) splits at 

 different points of the circumference, the Jacinise cohering at the 



