DIDYMIUM] didymiaceae 131 



Peck in Rep. N. York Mus., xxxi. 41 (1879) ; Macbr. I.e., 92. 

 D.fulvellum Mass. I.e., 237 (1892). 



Var. xanthopus Lister : stalk orange, columella white. — 

 Cionium xanthopus Ditm. I.e., 87, t. 43. C. iridis Ditm. 

 I.e., 13, t. 7. Diderma lobatum Somm. Suppl. Fl. Lapp., 240 

 (1826) ? Didymium xanthopus Fr. Sy t.Myc.,iii. 120; Macbr. 

 I.e., 91. D. iridis Fr. I.e., 120. D. lobatum var. stipitatum 

 Fr. I.e., 123 ? D. pertusum Berk. I.e., 313 ; Mass. I.e., 241. 

 D. proximum Berk. & Curt, in Grev., ii. 52 (1873) ; Rost. 

 Mon., App. p. 23. D. elegantissimum Mass. I.e., 243. 



PI. 102. — a. sporangia (England) ; b. capillitium and spores with fragment of 

 sporangium-wall ; c. spore ; d. sporangia of var. eximium (Mexico) ; e. sporangia of 

 var. xantfurpus ; f. capillitium and spores of same ; g. spore of same ; (England). 



The above varieties have been, distinguished by specific names, 

 depending on the colour of the stalk, columella, and capillitium. The 

 capillitium may vary however from white to purplish-brown in the 

 same group of sporangia, and the colour of the stalk and columella is 

 also inconstant. The specimen B.M. 885, from Ravenel, South Carolina, 

 is intermediate between the typical form and the var. eximium, having 

 some sporangia with dark brown and others with deep orange stalks 

 and columellae on the same leaf. D. eximium Peck and D. fulvellum 

 Mass. have orange-red stalks, with the columellae orange or buff. 

 The type of D. proximum Berk. & Curt, from South Carolina (K. 1493) 

 has orange-red stalks and a pale buff columella. The type of D. 

 pertusum Berk, from Appin, N.B. (K. 463) has orange stalks and a 

 white columella ; it corresponds with the description of D. xanthopus 

 Fries in all essential characters. D. elegantissimum Mass. from 

 Charlottenburg (K. 1) is the same variety. These forms blend into one 

 another so completely that they are here united under D. nigripes. 

 In this species the upper part of the stalk as well as the columella 

 occasionally contains crystals of lime, as in D. melanospermum. 



Hab. On dead leaves and twigs. Common. — Lynton, Devon (B.M. 

 1338) ; Lyme Regis (B.M. 1339) ; Epping Forest, Essex (B.M. 1337) ; 

 Wilts (B.M. 2488) ; North Wales (B.M. 2489) ; France (Paris Herb.) ; 

 Germany (B.M. 1558) ; Switzerland (B.M. 555) ; Portugal (B.M. 

 2490); Ceylon (B.M. 561); Singapore (B.M. 1935); Philippine 

 Islands (B.M. 2038) ; Ohio (B.M. 1341) ; South Carolina (B.M. 884) ; 

 Dominica (B.M. 1750) ; Brazil (B.M. 1776) ; Chili (Strassb. Herb.) : 

 var. eximium. — Wanstead, Essex (B.M. 2491) ; Muskoka, Canada 

 (B.M. 2493) ; New Jersey (B.M. 566) ; South Carolina (B.M. 885) ; 

 Colorado (B.M. 2492) ; Mexico (B.M. 2494) : var. xanthopus. — Somer- 

 set (B.M. 59); Staffordshire (B.M. 1342); Edinburgh (K. 440); 

 Appin, N.B. (K. 463); Germany (Strassb. Herb.); Italy (K. 334) ; 

 Switzerland (Herb. Zurich) ; Portugal (B.M. 2495) ; Ceylon (B.M. 

 577) ; Penang (B.M. 1730) ; Australia (B.M. 562) ; Philippine Islands 

 (B.M. 2042); Japan (B.M. 2001); Massachusetts (B.M. 1343); New 

 York (B.M. 564) ; South Carolina (K. 1492) ; Antigua (B.M. 1665) ; 

 Brazil (B.M. 2496) ; Bolivia (B.M. 2497). 



9. D. squamulosum Fr. Symb. (Gasterom.), 19 (1818). Plas- 

 modium colourless. Sporangia gregarious, subglobose or 

 hemispherical, umbilicate beneath, 0-5 to 1 mm. diam., 



