Dr. Smith's Character* cf Hookeria. 273 



that "the character is not to make the genus ;" a maxim no less 

 important than the other, as guarding against the division of a 

 natural genus, on account rtf any character whatsoever, and to 

 which Dr. Mohr's own practice is all along no less correctly con- 

 formable than to the former part of the said law. 



The genus which I have now to propose comprehends, among 

 other species, two mosses never suspected hitherto of being con- 

 geners, but both in habit so strikingly alike, that no plants could 

 be expected to form a more natural genus. These are the 

 Hypnum lucens of Linnaeus, and the Anktangium bulbosum of 

 Hedwig. I have hinted in the Flora Britannica that the former 

 of these might, even upon the principles of Hedwig, constitute 

 a genus; for in the only dried capsule which I could then afford 

 to dissect, I found the teeth of the inner perislomium so short, as 

 to differ greatly in that respect from every Hedvvigian Hypnum 

 or Leskea; but this arose from a partial cohesion. Jn copious 

 living specimens, brought last February by Mr. W. J. Hooker 

 from bogs near Holt, I have had an opportunity of examining 

 every part of this curious and beautiful moss at leisure. I have, 

 under the microscope in a warm room, seen the fringes in every 

 stage of expansion, and closing suddenly on the admission of 

 moisture, and I find the inner one divided about half way down 

 into 16' regular equal perforated teeth, as in many Leskece, 

 though far less deeply than in others. This inner membranous 

 fringe is so strongly plaited, that the lower parts of the teeth, in 

 a dry state, often approach one another so as to seem united. 

 Perhaps such a partial cohesion gave an irregularity to its ap- 

 pearance, and induced Dr. Schwa?grichen, the editor of the 

 Species Muscorum, to make it a Hypnum, not a Leskea, which 

 last, according to the generic rules of Hedwig, I now find it 

 ought to be. Hedwig appears never to have examined the frue- 



vol. ix. 2 n tiheation 



