comatricha] stemonitaceae 159 



irregular lax reticulation. Another intermediate form is B.M. 2625, 

 from Switzerland, a gathering resembling S. fusca in capillitium, 

 but the spores having a faint reticulation exactly like that of 

 typical C. typhoides var. heterospora. The specimen named G. dictyospora, 

 gathered by Dr. Celakovsky near Tabor, Bohemia (B.M. 2626), has 

 small scattered sporangia with spores of the var. heterospora character, 

 but with dark lax capillitium resembling that of C. laxa. In the 

 present state of our knowledge we may regard these gatherings as 

 forms of one variable species. The var. similis has hitherto been 

 found only in the United States : the sporangia somewhat resemble 

 those of C. pulchella var. gracilis, but differ in being much longer and 

 in having spores marked with warts of unequal size. 



Hob. On dead wood : var. microspora on dead leaves. — Ley ton- 

 stone, Essex (B.M. 1392) ; Lyme Regis, Dorset (B.M. 2627) ; Luton, 

 Beds (B.M. 2628) ; North Wales (B.M. 2629) ; Germany (B.M. 629) ; 

 Switzerland (B.M. 2630); Poland (Strassb. Herb.); Portugal (B.M. 

 2631); Italy (B.M. 628); India (K. 1580); Java (B.M. 2633); New 

 Zealand (K. 727) ; Japan (B.M. 2632) ; Iowa (B.M. 1394) ; Phila- 

 delphia (B.M. 1393) ; Antigua (B.M. 1674) ; Brazil (B.M. 2634) : 

 var heterospora — Witley, Surrey (B.M. 2635) ; Swarraton, Hants (B.M. 

 2638) ; Northumberland (B.M. 2639) ; Scotland (B.M. 2636) ; 

 Switzerland (B.M. 2637) ; Portugal (B.M. 2624) ; Bohemia (B.M. 

 2626) ; Massachusetts (B.M. 2640) ; Virginia (B.M. 1914) : var. 

 microspora— Lyme Regis (B.M. 1395) ; Berlin (B.M. 638) ; Ohio (B.M. 

 2641) : var. similis— Iowa (B.M. 1007) ; South Carolina (B.M. 632). 



9. C longa Peck in Rep. X. York Mus., xliii. 24 (1890). 

 Plasmodium ? Sporangia clustered, stalked, cylindrical, 

 elongated and slender, flexuose or drooping, 2 to 5 cm. long, 

 black ; sporangium-wall evanescent. Stalks very slender, 

 1 to 3 mm. long, black, rising from a well-developed mem- 

 branous hypothallus. Columella continued to near the apex 

 of the sporangium, very slender and wavy with zigzag 

 flexures in the upper part, tapering in breadth from 20 /x 

 at the base to 2 ^ near the summit. Capillitium a lax network 

 of dark brown threads, the terminal branches rigid, free, 

 forking at an acute angle. Spores dark grey, spinulose, the 

 spines connected at their bases by faint bands forming 

 a close reticulation, 8 to 9 fi diam. — Macbr. N. Am. Slime- 

 Moulds, 125 ; Petch in Ann. Perad., iv. 353. Stemonitis 

 loiuja Mass. Mon., 83 (1892). Comatricha equinoctialis Tor- 

 rend El. Myx., 138 (1909). 



PI. 122. — a, b. sporangia (Philadelphia) ; c. capillitium from upper part of spor- 

 angium ; d. capillitium from lower part of sporangium ; e. spores. 



From the absence of any superficial net in the capillitium this 

 species is placed in Comatricha, though in its fasciculate habit it 

 resembles a Stemonitis. The capillitium varies in different gather- 

 ings ; in some the threads are comparatively short, rigid throughout, 

 and anastomising but little ; in others they form a profuse network 

 with many membranous expansions and very slender free ends, but 

 the character of the dark reticulated spores remains constant in all 

 forms. 



