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GRIMMIA DUPRETI, N. SP. 
I. Theriot. 
Explanation of Plate' Viii. 
Grimmia Dupreti n. sp. 
1. Entire plant X 18. 
2. 2, 2. Leaves X 32. 
3. Transverse section of a leaf X 95- 
4. Perichaetial leaf X 32. 
5. Basal aerolation of a leaf X 208. 
6. Aerolation in the middle X 208. 
7. Aerolation of the apex X 208. 
8. 8. Perigonial leaves X 32. 
9. Antheridia X 32. 
10. Capsule in dry state X 18. 
11. Lid X 18. 
12. Transverse section of the capsule X 32. 
13. Portion of the peristome X 95. 
All figures slightly reduced. About one-fifth. 
Monoica, obscure viridis, densiuscule caespitosa. Caulis simplex, brevis- 
simus, erectus, 3-4 mm. longus. Folia sicca imbricata, madida erecto- 
patentia, 1.2 mm. longa, 0.40-0.45 mm. lata, lanceolata, breviter acuminata, 
carinata, obtusa, marginibus integris revolutis, costa basi angusta 24/* lata, 
ad apicem dilatata, sub summo apice evanida, cellulis inferioribus re'ctangu- 
lis, hyalinis a basi et marginibus, 30-40/* longis, 10-12/* latis, cseteris parvis, 
quadrato-rotundatis, valde chlorophyllosis, parietibus incrassatis, 6-8/* latis, 
laevibus, unistratosis. Folia 'perichsetialia subsimilia caulinis, sed multo 
majora, acuta, apicibus breviter hyalinis, basis longius hyalinis, revoluta 
in dimidio superiore, 1.5-1.8 mm. longa, e basi semi-vaginente, Cap- 
sula in pedicello brevi, 0.6 mm. longo, recto, immersa, erecta, ovato-sub- 
globosa, parva, basi rotundato, dilatata ori post maturitatem, sicca plicatula, 
paulo angulosa, deoperculata, 0.8 mm. longa, 0.40-0.44 mm. crassa, oper- 
culo convexo oblique sat longe rostrato. Peristomii dentes 16, integris, 
rubescentes, lseves ; annulus non observari. Calyptra ignota. Sporae lseves, 
12-14/* crassae. Flos mascules sub femineo sessilis, foliis perigonialibus 
brevibus, ovatis, obtusis, latissimis, valde concavis, cum nervis tenuibus et 
angustis; 5-6 antheridiis. 
Hab. On mill stone grit, Oka, near Montreal (Canada). Leg. H. 
Dupret, 2 August, 1905, No. 95. 
Pretty small species, remarkable by its perichaetial leaves much larger 
than the stem leaves, its very small capsule, its seta nearly equal to the cap- 
sule and consequently more developed than in most species of the subgenus 
Sckistidium. 
It resembles by some characters the Grimmia atricha Kdb., from which 
it is easily distinguished by its revoluted leaves, its smaller capsule, its 
longer seta and its peristome with red teeth. 
•Havre, France, le iojanvier, 1907. 
