PERICniENA.] 
ARCYRIACEiE. 
195 
Mass., Mon., p. 138. Physcmim congestum Somm., Fl. Lap., p. 241 
(1825). Lachnobohts congesta Berk. & Br., in Ann. Mag. Nat. Hist., 
Ser. 4, xvii., p. 140 ; Cooke, Myx. Brit., p. 74. Arcyria Hariotii 
Mass., Mon., p. 155. Lachnobohts Sauteri Host., in Fuckel, 
Symb. Myc. Nachtr., p. 76. 
Plate LXX., B.—a. sporangia, x 20 ; h. capillitium with portion of 
sporangium-wall and spores, x 600 (England). 
The type specimen of Arcyria Hariotii Mass., in Paris Herb., is 
typical L. circinans. 
Hah. On dead wood.— Haypit, Stafford (L:B.M.162) ; Somerset 
(B. M. 291) ; France (Paris Herb.) ; Tyrol (Strassb. Herb.) ; Iowa 
(B. M. 1027, 1028). 
SPECIES NOT MET WITH IN THE QUOTED COLLECTIONS. 
2. L. Arcyrella Rost., Mon., p. 431 (1875). Sporangia 
pyriform, fulvous or almost straw-coloured ; stalk about as long 
as the sporangium, yellowish ; capillitium not elastically expand- 
ing, forming a lax irregular network, threads 2*5 to 8*3 /a diam., 
attached at many points to the sporangium-wall, some threads 
descending into the tube of the stem, marked with numerous small 
obtuse warts ; spores smooth, 7 to 8 ^u, diam. 
Hah. Jutland. 
This description applies to Arcyria alhida. 
3. L. Rostafinskii E,acib., in Rozpr. Mat.-Przyr. Ak. Krak., xii., 
p. 80 (1884). Sporangia stipitate, ovoid-conical, apex rounded, 
yellowish-grey, the lower part of the sporangium with a distinct 
membrane, hemispherico-patelliform, the upper part destitute 
of a membrane ; capillitium well developed, forming a net adnate 
to the sporangium-wall by numerous attachments, the upper part 
with many free rounded ends ; threads 4'2 to 8*2 /x diam., 
marked with slender ridge-like processes forming a reticulation ; 
spores smooth, yellowish, almost colourless, 7*5 to 8*3 /u, diam. 
Hah. On dead birch roots. — Near Cracow, Poland. 
This description suggests a form of Arcijiia flava Pers., in which 
developments sometimes occur closely corresponding with the above 
account. 
SPECIES EXCLUDED FROM THE GENUS. 
L. globosus Eost. = Arcyria albida Pers. 
Genus 39.— PERICH^NA Fries, Symb. Gaster., p. 11 (1817). 
Sporangia sessile, subglobose or plasmodiocarps ; sporangium-waL' 
of two layers, the outer thickened with dark angular granules, 
which are exceptionally absent in the upper part, the inner 
membranous ; capillitium of branching or simple threads, spinose, 
minutely warted, or nearly smooth, marked with irregular 
constrictions ; spores yellow, minutely warted. 
