196 ENDOSPOREAE [DICTYDIAETHALRJM 



Genus 32.— DICTYDIAETHALIUM Rostafinski Versuch, 

 5 (1873). Aethalium pulvinate, formed of erect columnar 

 sporangia ; sporangium- walls incomplete, dome-shaped at the 

 apex, continued down to the basal membrane in four to six 

 straight threads ; capillitium none. CLATHROPTYCHIUM 

 Rost.Mon., p. 225(1875). 



1. D. plumbeum Rost. Versuch. 5 (1873). Plasmodium rose- 

 red. Aethalium 1 to 3 cm. broad, 05 to 1 mm. thick, dull slate- 

 coloured or clay-coloured, iridescent, areolated with the 

 convex apices of the sporangia ; sporangia cylindrical, angled 

 by mutual pressure, 0*5 to 1 mm. high, 02 mm. broad ; spor- 

 angium-wall persistent and dome-shaped at the apex, sub- 

 cartilaginous, continued down to the basal membrane in four to 

 six straight threads 2 to 4 /a thick and triangular in section, 

 evanescent between the threads. Spores clay-coloured or 

 yellow in mass, when magnified pale yellow, spinulose, 9 to 

 12 fx diam. — Macbr. N. Am. Slime-Moulds, 152. Fuligo 

 plumbea Schum. Enum. PL Saell., ii. 193 (1803). Reticularia 

 plumbea Ft. Syst. Myc, iii. 88. R. entoxantha Berk, in Hook. 

 Joum. Bot., iii. 201 (1851). R. lurida Berk. & Br. in Journ. 

 Linn. Soc, xiv. 82 (1873). Licea rugulosa Wallr. Fl. Crypt. 

 Germ., ii. 345 (1833). L. applanata Berk, in Hook. Lond. Journ. 

 Bot., iv. 67 (1845). L. cinnabarina Berk. & Br. I.e., 86 (1873). 

 L. tenuissima Berk. & Br. I.e. Dictydiaethalium applanatum 

 Rost. in Fuckel Symb. Myc, Nachtr., ii. 69 (1873). D. 

 dissiliens Hazsl. in Oester. Bot. Zeitsch., xxvii. 85 (1877). 

 Clathroptychium rugxdosum Rost. Mon., p. 225 (1875) ; Mass. 

 Mon., 51. C. cinnabarinum Sacc. in Michelia, i. 545 (1879). 

 C. Berkeleyi Mass. I.e., 53 (1892). 



PI. 152. — a. part of an aethalium seen from above; b. tubular sporangia from an 

 aethalium ; in two of them the spores are dispersed and the caps and threads of the 

 sporangium-walls are left free ; c. sporangia from a stouter aethalium ; d. cap and 

 threads of sporangium-wall ; e. floor of aethalium areolated with the bases of the 

 sporangia ; /. spores and portion of a thread ; g. spores and portion of thread from 

 aethalium drawn at c. (England) ; h. spore and thread from a stout aethalium 

 (Sikkim, K. 1669) ; i. spore (England) ; k. spore from type of Clathroptychium 

 Berkeleyi Mass. 



The spores are dispersed by the threads giving way at the base 

 and the sporangia separating in tufts from the persistent shining 

 base of the aethalium. American specimens have been received from 

 Dr. Rex showing an abnormal development ; the sporangium-walls 

 are, to a great extent, continuous between the threads, and form a 

 lattice work with wide expansions. An unusually stout form from 

 Sikkim (K. 1669) was named Reticularia entoxantha by Berkeley, 

 but is referred by Rostafinski to the present species ; it is an olive- 

 black aethalium, 3 mm. thick, and bright yellow within ; the threads 

 of the sporangia are 10 /a diam., waved and thickened at the margins ; 

 the spores are yellow and spinulose, 9 to 1 1 fx ; similar aethalia have 

 been obtained by Prof. Thaxter from Corral, Chili. Clathroptychium 

 Berkeleyi Mass., from Ceylon (K. 1666), differs only from the robust 

 forms of D. plumbeum in the more strongly spinulose spores ; but 



