1820.] Physical Science during the Year 1819. 123 



in the Brasils, and figured 10 of them, in the Stockholm Trans- 

 actions for 1817. And a new species of trichomanes, found 

 in Jamaica, which had been sent to Desvaux by an English 

 botanist, as a well-known plant, is described by him under the 

 name of T. spiciforme; barren fronds pinnatifid, laciniae 

 linear, lanceolate, entire, blunt; fertile fronds denudated, indusia 

 disposed in 2 rows, alternate, spiked. Mem. Mosq. 



Musci. — The plants of this interesting family have been of late 

 much illustrated by the publication of Hooker and Taylor's 

 Muscologia Britannica, and Hooker's Musci Exotici, the exe- 

 cution of the latter being peculiarly beautiful ; nor must the 

 poor but indefatigable collector, Hobson, of Manchester, be 

 forgot, his Collection of dried Specimens of British Mosses 

 and Hepaticoe, being of the greatest assistance to the students 

 of this minute tribe. 



Mr. R. Brown has newly given the characters and description 

 of lyeliia, a new genus, and observations respecting the section 

 of this order to which it belongs. To this he has added, re- 

 marks on leptostomum, and a new genus, hymenostomum, the 

 type of which genus is gymnostomum microstomum; orthodon, 

 the type of which is splachnum squarrosum. This eminent bota- 

 nist has also described the leaves of buxbaumia aphylla, a plant 

 which has hitherto been supposed to be leafless. This latter 

 observation has also been made by Mr, Stewart. The leaves are 

 palmate, much lobcd, and reticulated like the substance of a 

 jungermannia. Mr. Stewart also observed sometimes more than 

 one fruitstalk on the same bulb in different stages of vegetation, 

 and, therefore, concludes, that it cannot be an annual plant, as 

 hitherto described. 



Dr. Nies has published a thesis, in which he shows that many 

 musci appear at first merely as a greenisli organized slime or 

 jelly, with globules disseminated among it; they then assume a 

 fibrous form, and at last appear as true mosses : in their inter- 

 mediate state they have been taken for confervae, or ulvae. 



Hepaticce. — Nees von Esenbeck divides this family into two 

 sub-families, 1. Hepaticae elateratae, furnished with decussating- 

 spiral fibres included in a folliculus, so that they resemble the 

 ferns and their ring ; 2. Hepaticte nudae, which have not these 

 decussating fibres, so that they resemble the lichenes homallo- 

 phylli. He has improved the characters of the genera included 

 in the first sub-family, \\\\\c\\ nvc Jungermmmia, capsule 4-valved, 

 naked ; Stuiirophora, capsule 4-valved, affixed to the under part 

 of a cross-like receptacle towards the ends ; the type of the 

 genus being S. pulchella, the marchantia cruciata of Linnaeus ; 

 Marchantia, capsule opening at the tip, tiptoothed ; affixed 

 to the under surface of a receptacle placed on a footstalk; 

 DuuuUia, a new genus by the author, capsules 1 or 2, cut off at 

 top, immersed in a globose cucuUate receptacle placed on the side 



