BRITISH SPECIES OF THE GENUS MNIUM. 41 
Taste XV. 
Description of Mnium affine, Bland. 
A.— Specific limits of variation. 
[Cheshire, 3 stems; e Vogeso superiore, 2 stems.] As the number of 
specimens is so small, the figures in this Table are merely given for com- 
parison with further measurements. According to Messrs. H. N. Dixon 
and H. G. Jameson (* British Mosses, 2nd ed. p. 379), this species 
varies very greatly. There were no noticeable differences between the 
specimens from the two mentioned localities. 
1. Length of the leaves: 544-824 mm. 
. Breadth of the leaves: 2:20-4:-08 mm. 
2» a » at their base: 0°76-1:16 mm. 
m » cells: 30-43 y. 
. Number of cells: 56-93. 
. Breadth of the border: 47-92 y. 
. Number of cells of the border: 5-10. 
w marginal teeth : 42-106. 
» double marginal teeth : 0. 
OMNAHBR AR wb 
pia 
E 
a teeth on the nerve at the back of the leaves: 0. 
E 
[um 
. Length of the nerve: ? (indistinct). 
= 
bo 
. Tooth at the summit of the leaves: always existing. 
. Number of leaves: 24-29, 
53 fruits: 1-4. 
= m 
P Co 
B.—Gradation of the characters. 
[One patch: Tatton Park, Cheshire, 3 stems.] 
Mean interval curves. 
Intervals: 1. 2: 3. 4, 5. 6. T. 8. 9. 10. 
Length leaves (mm.)...... 2:02 3:390 3°88 8:80 414 387 447 444 551 6038 
Breadth leaves (mm.) .... 1:007 2-61] 2:90 2-58 2:64 2:45 2:01 2:58 303 2:93 
25: "base mm: a. 2 ee 1:04 1:12 1:24 136 (1:10 118 1:06 0:02. 0:86 0:89 
3 CELIAC) 3 ee ds 84. 3805855 1894. 932 31 23925 $30 3b, 88 
Number. cella? occ... ose 5. 4070 0 a d 70. 70 3D yer *72 
Breadth border (y) ...... 60: Gor 0S7 76. 78 000 789 4 72*. 0T 
ias border |... E cU, 9 9 9 0. 8b 18908 85. 52- TI 
Marginal teeth .......... 5 995 056 08. GL- .65 . 05 ? 78 62 
Double marginalteeth.... 0 0 0 0 0 0 0 0 0 0 
llipsnpinerve iaoe oc-+ eere 0 0 0 0 0 0 0 0 0 0 
Iancih'nerve...........- F — E -— — — — — — — 
Tooth summit ........ eos cto FA T c^ c o4 t4 — 
