Mr. Hooker's Observations on Andraa. 383 



" Silt lira laterales, ex medio sursum deorsumcifue versus dehis- 



centes. 

 " Coujtinctorium oKtusiusculum. 

 " Dissepimentum nullum. 

 " Sti/liscus C3'lindiicus. 

 " Spora subtilissima." 



With the above definition oi Andrcca before him, it is a matter 

 of surprise that Hedwig, in the Species Muscorum, should have 

 altered the characters to 



" Capsula exigua, minuta. Perist. dentibus quatuor concavis, 

 apice connexis, operculigeris :" 



thus mistaking the apophysis for a capsule, and the four 

 valves of the capsule for the teeth of a peristomium. He has, 

 however, rightly arranged it among the Miisci. 



Bridel must have been entirely unacquainted with Andraa; 

 or, surely, after having entered so deeply into the physiology of 

 Mosses as he has' done in the first volume of his Mtiscologia, he 

 would have admitted the genus into that work. Had he once 

 examined the fructification of Andrcea, he would immediately 

 have discovered that the characters of the order, to which it pro- 

 perly belongs, are accurately described in the chapter of his work 

 entitled " Quid sit Miisciis." 



Dr. Roth comes next to be noticed, who, in the third volume 

 of his Flora Gcrmanica, has given a very full account of the 

 genus, but has placed it among the Heputicce, on account of the 

 capsule's opening into four valves. In order to do this, however, 

 he supports an opinion that the conjunctorium of Ehrhart is not 

 an operculum, and that it docs not perform the office of that part 

 of a moss. But, till we are more fully acquainted with the use 

 of the operculum, and till wc are certain that the conjunct or itan of 



3 D 2 Ehrhart 



