Zyyodon.-\ D I PL O PERI STOMI. 123 



XXIV. ZYGODON. 



GEN. CHAR. Fruitstalks terminal; Peristome double; the 

 exterior of 1 6 teeth approaching in pairs ; the interior of 

 8 or 16 ciliary processes lying horizontally; Calyptra 

 dimidiate, smooth. (TAB. III.) 



The very singular plant which forms the subject of this genus 

 was called Bryum hy Dickson ; and by Smith Mnium, on account 

 of its furrowed capsule. The form of this capsule, and its being 

 erect, correspond well with Orthotrichum, with which, likewise, 

 it has the greatest affinity in its peristome. The character which 

 at once distinguishes this genus from Orthotrichum is its dimidiate 

 calyptra, exactly as Weissia is discriminated from Grimmia, and 

 Didymodon from Trichostomum. Three species are now known 

 to botanists. 



1. Zygodon conoideum ; leaves acute, cilise eight. (TAB. XXI.) 

 Zygodon conoideum. Uooker and Tayl. Muse. Brit. ed. 1. p. 74*. 

 Moug. et Nestl n. 721. Schwaegr. Suppl v. '2. t. 136. Hook. Fl. 

 Scot. P. II. p. 136. Hobson, Brit. Mosses, v. 1. n. 53. Am. Disp. 

 Muse. p. 15. Hook, and Grev. in Edin. Journ. of Science, v. 1. p. 132. 

 Amphidium pulvinatum. Sturm. Deutschl. Fl. (with a figure. J Funck, 

 Deutschl Moose, t. 22. n. 1. 

 Gagea compacta. Raddi. 



Mnium conoideum. Smith, Fl. Brit. p. 1345. Engl Bot. t. 1239. 

 Bryum conoideum. Dicks. Crypt. Fasc. 4>. t. \\. f. 2. Turn. Muse. 

 Hib.p. 112. 



Gymnocephalus conoides. Schwaegr. Suppl. v. 1. P. II. p. 87. 

 HAB. Trunks of trees, near Inverary, Scotland. Mr. 

 Dickson. Pear-trees at Orange Grove, near Belfast. 

 Mr. Templeton. Trees in Glen Falloch, near Loch 

 Lomond, and at Lorn, Scotland. Capt. Carmichael. 

 Near Manchester. Mr. Hobson. 



The stems of this moss grow in a tufted manner, like those 

 of Gymnostomum viridissimum, but rarely exceed half an inch 

 in length. Leaves erecto-patent, between ovate and lanceolate, 

 plane or slightly keeled, entire; the nerve reaching to the 

 point. Their texture is compact, dotted, exactly as in the 

 leaves of Gymnostomum viridissimum. Fruitstalk terminal^ 



