82 ENDOSPORE.E. [CHONDRIODERMA. 



Sub-genus 2. Leangium. Sporangia stipitate or sessile; 

 sporangium-wall of two closely connected layers (which do not 

 separate, except in C. Sauteri} ; the outer cartilaginous, more or 

 less charged with innate minute lime-granules ; the inner mem- 

 branous, often dehiscing in revolute lobes from the naked globose 

 mass of spores. 



9. C, Trevelyani Host., Mon., p. 182 (1875). Plasmodium ? 

 Total height 1 to l - 5 mm. Sporangia globose or subellipsoid, 

 sessile or shortly stalked, verrucose or nearly smooth, 1 mm. 

 diam., reddish or orange-brown ; sporangium-wall splitting irre- 

 gularly or in unequal, revolute, petal-like lobes, white on the 

 inner side : of three inseparable layers, the outer one cartilagi- 

 nous, brown ; the inner delicately membranous, attached to the 

 threads of the capillitium ; the middle layer thick, composed of 

 coarse irregular crystals of lime. Stalk equal, furrowed, O'l to 

 0'5 mm. high, O'l to 0*15 mm. thick, of the colour of the 

 sporangium. Columella none. Capillitium profuse, purple or 

 purplish-brown, somewhat rigid, forming a network with dark 

 bead-like thickenings at the nodes and on the threads, rarely 

 slender, with few thickenings. Spores dark violet-brown, spinu- 

 lose, 10 to 13 /x diam. Cooke, Myx. Brit., p. 40; Mass., Mon., 

 p. 202. Leangium Trevelyani Grev., Scot. Crypt. Fl., tab. 132 

 (1825). Diderma Trevelyani Fr., Syst. Myc., iii., p. 105. Chon- 

 drioderma (Erstedtii Host., Mon., p. 184, figs. 154, 157; Cooke, 

 Myx. Brit., p. 41 ; Mass., Mon., p. 203. Diderma geasteroides 

 Phill., in Grev., v., p. 113. Chondrioderma geasteroides Phill., in 

 Mass., Mon., p. 201. Diderma laciniatum Phill., I.e., p. 113. 



Plate XXXII., B. a. sporangia, x 20 ; 1). capillitium and spores, x 280 ; 

 c. fragment of sporangium-wall showing the cartilaginous and crystalline 

 layers, x 280 ; d. spore, x 600 (California ; type of Diderma geasteroides 

 Phill.) ; e. sporangium, x 20 (Shrewsbury, England). 



The crystalline middle layer of the sporangium- wall separates this 

 from all other species of the Leangium group. The type specimen 

 of C. Trevelyani described and figured under the name of Leangium 

 Trevelyani in Greville's Scottish Crypt. Flor., tab. 132, is in the Edin- 

 burgh Herbarium ; it is sessile vnMnium unchdatum, and was gathered by 

 "W. C. Trevelyan, Esq., who also sent specimens to Mr. Sowerby. The 

 specimen named Diderma Trevelyani, " Sowerby Herb." (K. 1478), 

 is on Mnium undulatum, and is no doubt that referred to. Greville 

 speaks of and figures a " very minute columella " ; he was evi- 

 dently mistaken on this point, and Berkeley in describing Trevelyan's 

 gathering states : "I find no trace of a columella ; the bottom of 

 the peridium within is perfectly even." Examination of the type 

 in the Edinburgh collection confirms Berkeley's statement. The 

 specimen from Jedburgh (K. 1477) is marked by Rostafinski 

 Chondrioderma Oerstedtii, and is given by him as a type of that species 

 (Host., Mon., App., p. 21) ; it has the characteristic capillitium and 

 sporangium-wall of Greville's type. These characters are also present 

 in Diderma geasteroides Phill. and D. laciniatum Phill., from California, 

 in Herb. Phillips, These three specimens are clearly the same species 

 as C. Trevelyani. 



