PERICH^NA.J 
AHOYIUAUE^. 
199 
of P. fusco-atra in the collections differ in no respect from forms of 
P populina, and cannot be held as specifically distinct. The type 
specimen of Oligonema Broomel Mass. from Warleigh (B. M. 364) 
is typical P. popuUna with characteristic branching capillitium threads 
marked with irregular swellings and spinules, and with minutely and 
closely warted spores 14 to 15 diam. The specimen described by 
Cienkowski as Lkea panmrum, I.e., is given by Eostafinski as the 
type of a new species, Perichcena liceoides, characterised by the scanty 
capillitium of free threads and the spores measuring 9 to 10 ^ ; Zopf , 
on the other hand, quotes it as a synonym for P. impulina ; and this 
view is confirmed by the not infrequent occurrence of forms of the 
latter species with scanty or no capillitium, and spores measuring from 
10 to 12 
Hah. On dead wood and bark. — Batheaston, Somerset (B. M. 309, 
320); Shrewsbury (B. M. 322) ; Lyme Eegis, Dorset (L:B.M.165) ; 
Salisbury (L:B.M.165); Brentwood, Es.sex (L:B.M.165) ; Boynton, 
Yorkshire (B.M. 1160) ; Tregayan, Anglesey (B.M.) ; France (B.M. 
1161) ; Germany (B. M. 653) ; Finland (B. M. 767) ; Sweden (K. 1702) ; 
Tasmania (K. 1710); Philadelphia (L:B.M.165) ; Ohio (L:B.M.165) ; 
Florida (B. M. 987). 
4. P. variabilis Rest., Men., p. 295 (1875). Plasmoditim ? 
Sporangia sessile, globose on a narrow base, 0*5 mm. diam., 
or forming curved or net-like plasmodiocarps, scattered, ochrace- 
ous-yellow or pale timber; sporangium- wall of two layers, the 
outer charged with dark angular granules, closely combined 
with the membranous papillose inner layer ; in some cases the 
outer layer is not distinguishable in the upper part of the 
sporangium. Capillitium a profuse network of sparingly branched, 
yellow threads, 2 to 4 diam. , rough with minute scattered warts 
and irregular constrictions. Spores yellow, minutely warted, 
10 to 15 yu, diam. — Physarvmi vermiculare Schwein., in Trans. Am. 
Phil. Soc, N. Ser., iv., p. 257 (1834). Ophiotheca vermicularis 
Mass., Mon., p. 134. Perichcena vermicula^ns Rost., Mon., App., 
p. 34 (1876) ; Lister, in Jour. Bot. (1891), p. -265. Perichcena 
Friesiana Rost., Mon., p. 296. Ophiotheca umbrina Berk. & 
Curt., in Grev,, ii., p. 68. Licea reticulata Berk. & Br., in Journ. 
Linn. Soc, xiv., p. 86. Perichcena reticulata Rost., Mon., App., 
p. 35. Ophiotheca reticulata Mass., Mon., p. 133. Perichcena 
confusa Mass., Mon., p. 117. 
Plate LXXII., B.— a. sporangia, x 20 ; Z>. portion of papillose wall of 
the upper part of the sporangium, x 280 ; c. capillitium and spores, 
X 280 ; (I. capillitium and spore, x 600 (England). 
The yellow form of this species has appeared in some abundance 
in successive years at Lyme Regis, and corresponds exactly with the 
type specimen of Physarum vermiculare from Schweinitz (K. 1671). 
The German type of P. variabilis is not represented in the Stvassburg 
or British collections, but examination of the type of Ophiotheca 
umbrina from Curtis (K. 1705), which is given as a synonym for 
P. variabilis by Rostafinski (Mon., App., p. 35) shows that 'it is a 
pale umber, plasmodiocarp form, agreeing in the structure of the 
sporangium- wall, capillitium, and spores with the English gatherings. 
P. Friesiana Rost. is described as differing from P. variabilis in the 
