lbpidoderma] didymiaceae 139 



Germany (B.M. 599) ; Finland (B.M. 597) ; Poland (Strassb. Herb.) ; 

 Hungary (B.M. 1822) ; British Columbia (B.M. 2516) ; Ohio (B.M. 

 1358); Iowa (B.M. 1359); Colorado (B.M. 2515); Bolivia (B.M. 2513). 



The type of Spumaria Micheneri Berk., from Pennsylvania (in 

 Grev., ii. 52, 1873), is not represented in the quoted collections, 

 and the description is too brief to be of value ; the species should 

 therefore be discarded. 



Genus 17. — LEPIDODERMA de Bary in Rost. Versuch, 

 13 (1873). Sporangia stalked, sessile, or forming plasmodio- 

 carps ; sporangium-wall cartilaginous, beset with superficial 

 crystalline discs or scales ; capillitium rigid and without lime 

 (except in L. Carestianum var. granuliferum) . 



KEY TO THE SPECIES OF LEPIDODERMA. 



Sporangia with orange stalks. 1. L. tigrinum 



Sporangia rarely with short drab stalks, usually sessile 

 or forming plasmodiocarps. 2. L. Carestianum 



1. L. tigrinum Rost. Versuch, 13 (1873). Plasmodium 

 orange-yellow. Sporangia scattered, subglobose, flattened 

 and umbilicate beneath, stalked, rarely sessile, 1 to 1-5 mm. 

 diain., olive- or purplish-grey, glossy, more or less closely beset 

 with rounded, angular, or star-shaped crystalline scales of 

 lime ; sporangium-wall cartilaginous, of two closely combined 

 layers, orange-yellow. Stalk stout, cylindrical 0*2 to 0*7 mm. 

 high, furrowed, orange-brown, of a spongy texture within, 

 containing deposits of lime ; rising from a hypothallus which 

 is either vein-like or effused and of a loose reticulated structure. 

 Columella hemispherical, orange, of the same texture as the 

 stalk, containing deposits of lime in rounded nodules. Capilli- 

 tium profuse, of straight or flexuose threads, sparingly 

 branched, dark purple-brown or grey. Spores dark purplish 

 grey, minutely and closely spinulose, 10 to 13 /a diam. — Rost. 

 Mon., p. 187 ; Mass. Mon., 253 ; Macbr. N. Am. Slime-Moulds, 

 106. Didymium tigrinum Schrad. Nov. Gen. PL, 22 (1797) ; 

 Er. Syst. Myc, hi. 117. D. rufipes Fr. I.e., 116. D. versipelle 

 Fr. I.e., 117 ? Physarum squamulosum Pers. Syn., 174 (1801). 

 P. tigrinum Pers. I.e. Leangium squamulosum Fr. Stirp. 

 Femsj., 83 (1827). Diderma citrinum Berk, in Sm. Engl. 

 Fl., v. pt. 2, 310 (1836) {non Schum.). Lepidoderma fulvum 

 Mass I.e., 253 (1892). 



PI. 114. — o. sporangia (North Wales) ; b. capillitium and spores with fragment, of 

 sporangium-wall showing crystalline scales ; c. spore. 



This species occurs not unfrequently in company with Diderma ochra 

 ceum (q.v.) to which it appears to be closely allied. The specimens of L. 

 fulvum Mass., from Scarborough (Herb. Mass.), and from Belle Croix, 

 France (K. 1555 ; Paris Herb.), are immature gatherings of the present 



