DiCRANACEiE.J 173 ICeratodon. 



lineal-lane, gradually acuminate, acute, indistinctly denticulate or 

 entire at apex, carinate, plane at margin, cells at base elongato-rectan- 

 gular, pellucid, above quadrate or roundish, chlorophyllose ; nerve 

 vanishing in the apex. Perich. bracts like the leaves ; caps, on a rather 

 short pale seta twisted to left when dry, very small, erect, ovate, 

 short-necked, pale ferruginous, deeply striate ; annulus very narrow, 

 persistent, lid broadly conic with a curved subulate beak ; teeth from a 

 very broad base, suddenly subulate, erect when moist, incurved when 

 dry, rufous red, very fugacious. 



Male infl. minute, near the female, bracts resembling the leaves. 



Hab. — Fissures of rocks in subalpine districts. Fr. 6 — 7. . 



Devonshire, Wales, Ireland, N. of England and Scotland. 



This little plant is only about a quarter of an inch high, yet its small 

 yellow green tufts when loaded with capsules are conspicuous in the rock 

 crevices of most of our mountains. The peristome is so fragile that it usually 

 disappears as soon as the lid falls off. 



CERATODON Bridel. 



(Bry. univ. i, 480 — 1826.) 



Plants csespitant, terrestrial ; leaves lanceolate, nerved, minutely 

 areolate, smooth. Calyptra cucullate, rostrate. Capsule ovate-oblong, 

 striate, sulcate when dry, with a more or less prominent neck, annulate, 

 pachydermous ; teeth of peristome arising from a short basal membrane, 

 16, regular cleft nearly to base into two filiform legs, closely articulate 

 below, becoming more remotely so upward and papillose. Der. xcpas a 

 horn, oSovs a tooth, from resembling a goat's horn. 



The genus Ceratodon links the Dicranaceffi to the Tortulaceas, approach- 

 ing the former by the genus Oncophorus in the leaf, capsule and peristome, the 

 slender legs of the latter with increasing papillosity clearly indicating a 

 transition to the latter family, strengthened still more by the habit, foliage 

 and areolation. C. corsicus Schimp. is found in S. Europe, but C. chloroPus 

 Brid. is placed by Lindberg in a new genus Cheilofkela, between Swartzia and 

 Ditnchum. 



Clavis to the Species. 



Nerve reaching apex. Caps, subcernuous, with a nodose neclc. purpureus. 



Nerve excurrent. Caps, erect, with a short equal neck. conicus. 



I. CERATODON PURPUREUS (L.) Brid. 

 Dioicous ; leaves oblong-lanceolate, margin entire, or slightly den- 

 ticulate at point, nerve reaching apex. Capsule on a purple seta, sub- 

 cernuous, oblong with a short unequal neck, substrumose and sulcate 

 when dry. (T. XXVI, D.) 



Syn. — Musciis trichoides parvus foliis musci vulgaris, capitulis longis acutis. Doody in Ray 

 Syn. app. 243 (1690). 



