Parr 2, 1913] DICRANACEAE 149 
1. Thysanomitrium Richardi (Brid.) Schwaegr. 
Suppl. 2!; 61. 1823. 
Campylopus Richardi Brid. Musc. Recent. Suppl. 4:73. 1819. 
Grimmia Richardi Spreng. Syst. 4: 154, 1327" 
Dicranum Richardi C. Mill. Syn. 1: 413. 1848. 
Dicranum laevigatum C. Mall. Syn. 2: 601. 1851. 
Campylopus laevigatus Schimp.; Besch.; Mém. Soc. Sci. Nat. Cherbourg 16: 167. 1872. 
-Physanomitrium yunqueanum C. Mill. Hedwigia 37: 225. 1898 
Campylopus yunqueanus Paris, Index Bryol. Suppl. 99. 1900. 
Pilopogon laevigatus Broth. in E. & P. Nat. Pfl. 13: 336. 1901, 
Pilopogon Richardi Broth. in E. & P. Nat. Pf. 13: 336. 1901. 
Pilopogon yunqueanus Broth. in E. & P. Nat. Pfl. 13: 336. 1901. 
Dioicous: male flowers 5 or 6 together in a compact terminal head, dark golden-brown, 
the inner perigonal leaves ovate, short-pointed, enclosing 8-10 antheridia about 0.6 mm. long 
with paraphyses slightly exceeding them: fertile plants in extensive mats, mostly dark chestnut- 
colored to blackish, or the younger leaves greenish, with robust, sometimes branching stems 
up to 8 cm. high bearing nearly straight, erect-spreading leaves rather uniformly placed along 
the stems or appearing somewhat comose at the flower-clusters: stem-leaves up to 8 mm. long, 
oblong-lanceolate, subtubulose, with a short, hyaline, serrulate point; costa about 350 » wide 
and scarcely tapering in the broader part of the leaf, somewhat ribbed on the back, in cross- 
section showing in the lower part of the leaf on the dorsal side a stereid-band interrupted by 
the differentiated outer cells, on the ventral side a very small stereid-band, often scarcely 
evident, without outer cells, while in the upper part of the leaf sections show both stereid-band 
and outer cells wanting; alar cells brownish, forming a distinct cluster; cells of the lower part 
of the blade elongate with walls mostly thickened and pitted, those toward the margin narrower 
and paler, scarcely forming a distinct border, becoming in the upper part of the leaf shorter 
and more or less obliquely elongate: archegonial flowers aggregate, with the inner leaves con- 
volute scarcely one half up, rather gradually narrowed to a lanceolate point, hyaline and rough 
toward the apex: seta solitary, cygneous or sinuate, mostly 6-8 mm. long, slightly rough above: 
capsule regular, elliptic, 1.5-2.5 mm. long, rough at the base, somewhat furrowed when dry, 
without stomata; annulus broad; lid conic-rostrate, about two thirds as long as the capsule; 
peristome-teeth about 40 «4 wide at base and 400 » high, papillose nearly or quite to the base 
or somewhat striate below and entire or more or less split along the distinct median line, some- 
times almost to the base: calyptra fimbriate on the lower margin: spores nearly smooth, 
about 10 uw in diameter. 
TYPE LOCALITY: Guadeloupe. : : P 
DistRIBUTION: Mexico; Costa Rica; Jamaica, Porto Rico, Guadeloupe, and St. Kitts; also in 
South America. : 
15. PILOPOGON Brid. Bryol. Univ. 1: 519. 1826. 
Dioicous. Plants mostly in broad, deep tufts with slender stems, branching above. 
Leaves straight, appressed or erect-spreading, lanceolate-subulate, denticulate at the apex and 
somewhat ribbed on the back; costa broad, with stereid-bands above and below the guide-cells; 
alar cells not differentiated or often forming a more or less distinct pale or reddish group; lower 
cells of the blade rectangular, rather thin-walled, sometimes slightly pitted; perichaetial leaves 
high-convolute, sometimes reaching the capsule. Seta elongate, erect, slightly flexuous, more or 
less roughened above. Capsule cylindric, slightly curved, smooth when dry, without stomata 
or annulus; peristome-teeth undivided, narrow, filiform above, densely papillose nearly to the 
base, at the base more or less striate, without a distinct median line. Calyptra fimbriate at 
the base. 
Type species, Didymodon gracilis Hook. 
1. Pilopogon gracilis (Hook.) Brid. Bryol. Univ. 1: 519. 1826. 
Didymodon gracilis Hook. Musci Exot. pl. 5. 1818. 
Pilopogon calycinus Schimp.; C. Mill. Syn. 2: 586. 1851. 
Pilopogon Mohrii C. Mill. Linnaea 38: 626. 1874. 
Pilopogon glabrisetus C. Mull. Bull. Herb. Boiss. 5: 551. 1897. 
Dioicous: male flowers 5 or 6 together in a compact, terminal head, golden-brown, the 
inner perigonial leaves ovate, short-pointed, faintly costate, enclosing 7 or 8 antheridia about 
