BKEFELDIA.] AMAUEOCH^TACEiE. 135 



SPECIES NOT MET WITH IN THE QUOTED COLLECTIONS. 



2^ A. minor Sacc. & Ellis, in Michelia, ii., p. 566. Effused, 

 varying, oblong, adnate-applanate, the margin almost naked, 

 externally clay-colour, very minutely punctate, internally blackish . 

 Capillitium threads filiform, sparingly branched and anastomosing, 

 very pale brown. Spores blackish, minutely warted, then quite 

 smooth, 15 /A diam. 



Hah. On twigs. — Utah. 



This description suggests an imperfect specimen of DictyduethaUum 

 plumbev/m. 



Genus 21.— BREFELDIA Rostafinski, Versuch, p. 8 (1873). 

 ^thalia pulvinate, consisting of suboylindrical, somewhat branched 

 and confluent sporangia, rising from a base of spongy barren 

 tissue, which is continued, chiefly among the lower portions of 

 the sporangia, in irregular folds, sometimes forming imperfect 

 sporangium-walls and central columellse. Capillitium of numerous 

 horizontal threads, uniting at the surface of the sporangium to 

 form many-chambered vesicles. 



1. B. maxima Host., Versuch, p. 8 (1873). Plasmodium white, 

 in rotten stumps of fir, beech, etc. ^thalia 2 to 16 cm. broad, 

 5 to 10 mm. thick, purplish-brown, composed of elongated 

 branching sporangia 0'3 to 0'5 mm. diam., extending upwards 

 from the spongy basal tissue, which is continued among them 

 as irregularly branching, purple-brown membranous folds, usually 

 forming distinct rigid columellse. Capillitium consisting of 

 numerous threads . radiating from near the central part of the 

 sporangium ; each thread expands at the boundary of the 

 sporangium into a many-chambered vesicle, which is continued 

 into a corresponding radial thread of the adjoining sporangium. 

 The proximal ends of the threads are slightly attached in clusters 

 of three or four by a fragile membrane. The vesicles are of firm 

 structure, often containing a spore in several of the chambers, 

 with no appearance of forming part of the sporangium-wall, 

 except where they occasionally coalesce in fewer or greater numbers 

 to form vertical scalariform strands. Spores purplish-brown, 

 minutely spinulose, 9 to 12 yu. diam.- — Mon., p. 213;, Cooke, Mjx. 

 Brit., p. 53 ; Mass., Mon., p. 91 ; Macbride, in Bull. Nat. Hist. 

 Iowa, ii., p. 389. Reticularia maxima Fr., Syst. Orb. Veg., i., 

 p. 147 (1825). Licea perreptans Berk., in Gard. Chron. (1848), 

 p. 451. 



Plate LI., A. — c. subdiagrammatic view of portions of four columnar 

 sporangia from an Eethalium.; each sporangium has a, central columella, 

 and is clothed on. the surface with numerous vesicles, from which short 

 capillitium threads pass into the adjacent sporangia ; at a is seen a 

 scalariform strand, formed by vertical union of a row of vesicles, x 50; 

 d. capillitium threads and vesicles, x 180 ; e. spore, x 600 (England). 



