[February, 1858.] 329 



ON MNIUM ORTHOEHYNCHUM, Brid. 



By Benj. Carbington, M.D., Fel. Bot. Soc. Ed., etc. 



{With a Plate.*) 



Considerable discussion lias taken place of late as to the claims 

 of this Moss to be regarded as a species. I think however it 

 will not be difficult to discover the means by which it has been 

 brought into discredit. Until lately it was one of the rarest of 

 British Mosses : only two stations are given in the Bryol. Brit., 

 that of Mr, Spence at Mowthorpdale, Yorkshire, plants from 

 which I have not seen, and Mr. Mitten's station at Cuckfield, 

 Sussex. Duplicates from the latter {M, riparium, Mitt.) have 

 been in more general circulation; and when it is known that 

 this is not the true Moss (if more than a variety of Mnium ser- 

 ratum), the cause of misunderstanding will be no longer obscure. 



Mr. Nowell has the credit of first finding the true M. ortho- 

 rhynchum in fruit, on Arncliflfe Clouder, West Yorkshire, June, 

 1856. In September of the same year I collected it at Malham, 

 with male flowers, and, in company with Mr. Nowell, near In- 

 gleborough (May 21), and Malham (July 20, 1857). All these 

 stations are on the Scar limestone, and within a circumference of 

 ten miles of each other. It is probably not uncommon in sub- 

 alpine countries of like formation, but overlooked as a state of 

 M. s erratum. 



* Explanation of the Plate. 



\_Note. — The figures marked (1) are magnified about 20 times ; those marked (3) 

 are magnified about 180 diameters.] 



(a, b.) Mnium orthorliynchwm, barren plant, a. s. L. Stem-leaf, and border, 

 magnified. J. Upper part of the stem, showing the perigonial leaves, natural size. 

 ( J 3.) Inner perigonial leaf, magnified 65 times, with antheridia at the base in 

 situ. h. (1.) Outer perigonial leaf, magnified 20 times. (3.) Part of border, 

 magiiified 180 times, an. Antheridia and paraphysis. 



(e, d) Mnium serratmn. c. Stem-leaf, magnified, d. p. i. Perichsetial leaf. 

 The figures to the left show the areolae stiU more magnified. At the base the 

 synoicous inflorescence is indicated. AN. Antheridia, and a. archegonia (magni- 

 fied 180 times), on the same receptacle, and surrounded by jointed paraphyses. 



(e.) Mnium ortJiorhynchum ; fertile plant, p. l. Perichtetial leaf and border, 

 magnified, a. Archegonia and paraphysis. 



(/.) Mnium riparium, Mitten, s. i. Stem-leaf. Portions of the border and 

 base of the leaf, the areolse magnified 180 times. 



N. S. VOL, II. 2 U 



