BRITISH SPECIES OF THE GENUS MNIUM. 
Taste XIX. 
Description of Mnium punctatum, Linn. 
À.— Specific limits of variation. 
[Seven localities in Great Britain.—Island Griisen (Sweden).] 
l. Length of the leaves: 4:35-9:21 mm. 
2. Breadth of the leaves: 2:71-6:48 mm. 
3. be jt ji at their base: 0:44—0:82 mm. 
4. 2 » cells: 36-65 u. 
5. Number of cells: 61-111. 
6. Breadth of the border: 82-195 p. 
7. Number of cells of the border: 8-11. 
8. T marginal teeth : 0. 
9. 2 double marginal teeth: 0. 
10. E teeth on the nerve at the back of the leaves: 0. 
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11. Length of the nerve: the nerve reaches the summit in the great majority of the cases, 
It always reaches the summit in the second leaf above the longest one and higher 
upwards. 
12. Tooth at the summit of the leaves: a tooth is almost always existing. It always 
exists in the second leaf above the longest one and higher upwards. 
18. Number of leaves: 7-19. 
14. 5 fruits: 1-2. 
B.—Gradation of the characters. 
[One patch : Llanberis to Bangor, 11 stems.] 
Intervals: 1. 2. 8. 4, 5. 6. yj^ 
Length leaves (mm.)...... 2:10 2:56 8:58 3863 459 498 578 
Breadth leaves (mm.) .... 1°68 198 298 317 335 359 3277 
Bo base (mm.) ...... 0:58 0:63 0:64 0:64 0:64 0:62 0-64 
a; cs GE UT) REN 90- 20 0000 46 40 47 A5 
NHMDOPGOIB. T. eel. 38 38 52 65 70 TE 80 
Breadth border (y). ....... SS ADD IIIS 0107. 194 :190 190 
Cells border ©. 2. os. se ek: 02 QNT so ess 93 90 p5 
Marginal teeth 55.42... 0 0 0 0 0 0 0 
Double marginal teeth .... 0 0 0 0 0 0 0 
BREST nerves... eec ete 0 0 0 0 0 0 0 
I[ienpth nerve... ......... — = — Lo nl ec 
ll/'ooth summit .......:..- tT— +- +— +— + te dum 
+— 
