220 WILLIAMS: THE GENUS DESMATODON 
linear, the base often a little broader, 4 mm. long and 1 mm. wide, 
rarely 5.5 mm. long and 1.5 mm. wide, the point rounded or broadly 
acute and mostly apiculate by the shortly excurrent costa; leaf- 
margin, except near the flat and not quite entire apex, with a dis- 
tinct, thickened and recurved border extending to near the base; 
costa papillose on the back to below the middle, in cross-section 
showing two or three guide-cells, usually a single layer of large 
cells on ventral side, but sometimes two layers, and on dorsal side 
a large stereid band with outer cells somewhat differentiated ; 
cells of upper part finely papillose on both sides, rhomboidal to 
hexagonal, the median about 16 u wide by 18-25 » long, the basal 
cells, often 20 » wide by 50-80y long, smooth and more or less 
tinged with golden brown: perichaetial leaves scarcely differen- 
tiated; seta somewhat flexuous, -8-15 mm. long; capsule nodding 
to horizontal, sometimes pendant, oblong, more or less curved, 
up to 2 mm. long without lid, the stomata in one row at the base; 
peristome reddish brown, the distantly articulate teeth often 
twisted almost once around and divided nearly to the base into 
two or three slender, terete, sometimes split or perforate forks or 
the forks sometimes united above; annulus persistent, of two or 
three rows of small cells; lid conic, short-pointed, the three or 
four basal rows of cells not elongate, those above elongate-rec- 
tangular, in very oblique rows; calyptra cucullate, extending about 
one half way down the capsule; spores papillose, 30-40 in diam- 
eter. [Fic. 12.] 
Type LocaLity: Tyrol, Austria. 
DistRIBUTION: Rocky Mountains of British America and 
Vancouver Island to Colorado; also in Greenland, Europe and Asia. 
ExsIccATAE: Drummond, Musci Am. 135. 
ILLUSTRATION: B.S.G. Bryol. Eur. pl. 135. 
Explanation of plate 11 
Cross-sections of Desmatodon made about half way down the leaf. 
Fic. 1. Desmatodon latifolius (Hedw.) Brid., from California, X 27° 
Fic. 2. Desmatodon suberectus (Hook.) Limpr., from Canada, X 270. 
Fic. 3. Desmatodon Guepini B. S. G., from California, X 270. 
Fic. 4. Desmatodon plinthobius Sull. & Lesq., from South Carolina, X 279- 
Pi & esmatodon obtusifolius (Schwaegr.) Jur., from Montana, X 270. 
Fic. 6. esmatodon Porteri James., from Pennsylvania, X 200. 
Fic. 7. Desmatodon systylius B. S. G., from Labrador, x 270 | 
Fic. 8. Desmatodon Garberi Lesq. & James, from Florida, X 279- 
Fic. 9. Desmatodon Sprengelii (Schwaegr.) R. S. Williams, from Santo Do- 
270. 
1G. 10. Desmatodon stomatodontus (Card.) R. S. Williams, from Mexico, X 359 
Fic. 11. Desmatodon cernuus (Hueb.) B, S. G., from Canada, X 270: 
Fic. 12. Desmatodon Laureri (Schultz) B. S. G., from Colorado, X 279- 
