98 ENDOSPORE^;. [DIDYMIUM. 



The specimens K. 471 to 474, called D. physaroides, differ in no 

 respect from the common, nearly sessile form of D. farinaceum ; with 

 a few exceptions the sporangia are confluent at their margins, but 

 confluent sporangia are often met with in D. farinaceum. 



Bab. On dead leaves, bark, etc. Highgate, London (B. M. 1068) ; 

 a. and |8. Lyme Regis, Dorset (L:B.M.75) ; a. Ascot, Berks (B. M. 70) ; 

 a. France (K. 6) ; a. Germany (B. M. 422) ; a. Maine, U.S.A. (K. 487) ; 

 a. and /3. Ohio (L:B.M.75) ; a. S. Carolina (B. M. 889) ; /3. S. Carolina 

 (B. M. 893). 



6. D, nigripes Fries, Sysfc. Myc., iii., p. 119 (1829). Plas- 

 modium grey, among dead leaves. Total height 1 to 1 '5 mm. 

 Sporangia hemispherical, umbilicate beneath, stipitate, erect, 

 gregarious, 0'5 to 0'7 mm. diam., white; sporangium-wall mem- 

 branous, mottled with brown, or colourless, beset with stellate 

 crystals of lime. Stalk cylindrical, one to three times the height 

 of the sporangium, longitudinally striate, varying in colour from 

 dark olive-brown to orange, horn clear. Columella subglobose, 

 dark brown, orange, or white, filled with irregular angular 

 granules of lime. Capillitium of delicate colourless or purplish- 

 brown branching threads. Spores pale violet-brown, nearly 

 smooth, 8 to 11 fM diam. Berk., in Sm. Engl. Fl., Fungi, p. 313. 

 Physarum nigripes Link, in Berl. Mag., iii., p. 27 (1809); Ditm., 

 in Sturm, Deutsch. Fl., iii., p. 35 (1816). P. microcarpon Fr., 

 Symb. Gast., p. 23. Didymium microcarpon Host., Moil., 

 p. 157 (1875); Cooke, Myx. Brit., p. 32; Mass., Mon., p. 226; 

 Macbride, in Bull. Nat. Hist. Iowa, ii., p. 146. Cionium xanthopus 

 Ditm., I.e., p. 37. Didymium xanthopus Fr., Syst. Myc., iii., 

 p. 120. D. pertusum Berk., I.e., p. 3 IB ; Cooke, Myx. Brit., p. 35 ; 

 Mass., Mon., p. 241. D. proximum Berk. & Curt., in Grev., ii., 

 p. 52 ; Host., Mon., App., p. 23 ; Macbride, in Bull. Nat. Hist. 

 Iowa, ii., p. 145 ; Mass., Mon., p. 238. D. eximium Peck, in 

 Rep. N. York Mus., xxxi., p. 41 ; Mass., Mon., p. 241. D. ful- 

 vellum Mass., Mon., p. 237. D. elegantissimum Mass., Mon., p. 243. 



a. genuinum : stalk and columella dark olive-brown. 



(3. eximium : stalk dark orange, columella orange or buff. 

 D. eximium Peck, I.e. 



y. xanthopus : stalk orange, columella white. D. xanthopus 

 Fr., I.e. 



Plate XXXIX., B. a. small and large sporangia of a. genuinum, x 20; 

 &. sporangium of 7. xanthopus, x 20 ; o. sporangium of the same, broken 

 and showing the white columella, x 20 ; cl. capillitium and spores, with 

 fragment of sporangium- wall, x 280 ; e. coarse capillitium (of less frequent 

 occurrence), x 280 ; spore, x 600 (England). 



Rostafinski's specific name, which he adopted from Fries, was given 

 by this author as a MS. synonym of his D. nigripes in Symb. Gast., 

 p. 23, and was never afterwards introduced into his works. Obviously 

 Fries's name must be restored. 



The above varieties have been distinguished by specific names, 

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



