350 
Massee and Salmon. — Researches on 
acute, ends. The spores of M. variabilis , seen in the mass, have 
a faint brownish tinge; we were not able to observe any layer of 
mucilage surrounding each spore, as Zukal has recorded in the case 
of M. longirostris. The asci are extremely evanescent, and difficult 
to see — the perithecium containing as a rule only free spores. The 
latter are usually broadly lunulate in outline, and somewhat flattened ; 
sometimes, however, they are slightly irregular in shape. The varia- 
bility in the shape of the perithecium is very marked — the ostiolum 
being sometimes papilliform or even hardly visible, at others well- 
defined and forming a distinct more or less cylindrical neck, which is 
sometimes flexuous. 
M. nidicola, sp. nov. (Figs. 62-65). 
Peritheciis nigris glabris carbonaceo-membranaceis sparsis matrice 
subimmersis subglobosis -J mm. diam. ostiolo brevi conico, contextu 
parenchymatico densissimo e cellulis polygonis nigro-fuscis plus 
minus opacis 8-10 latis composite; ascis numerosis subgelatinosis 
ellipticis vel globoso-ellipticis 10-13x6-8 ^ octosporis citissime dif- 
fluentibus; sporis minutis anguste sublunulatis utrinque acutis laevi- 
bus hyalinis vel stramineis 7-5-8 x 2 fx. 
Hab. — In nido vetusto Bombi sp., sociis Myxotricho setoso (Eidam), 
Schroet., et Arachnioto candido (Eidam), Schroet., Kew, Mar. 1901. 
M. longirostri, Zukal, sporis lunulatis comparanda, sed perithecii 
forma et glabritate, ascis minutis nec non sporis angustioribus major- 
ibus longe recedens. 
The above species occurred sparingly on an old nest of a Wild-bee 
(. Bombus sp.). The nest, which was dug up in the Royal Gardens, 
Kew, was covered on the surface with large patches of Myxotrichum 
setosum and Arachniotus candidus. The wall of the perithecium, 
unlike that of M. variabilis , is very dense and opaque, so that its 
cellular structure is not readily apparent. The asci are subgelatinous, 
and very quickly dissolve in water, setting free the narrow somewhat 
lunate-shaped spores. The spores become finally of a pale straw 
colour, and the ascus itself is sometimes tinged with the same colour. 
Spumatoria, gen. nov. 
Perithecia subglobosa, semi-immersa, demum superficialia, mem- 
branacea, in rostrum longum cylindraceum apice fimbriatum plus 
minus dilatatum attenuata, ascis tenuibus, evanescentibus, octosporis, 
sporis didymis, hyalinis, demum in spuma mucilaginosa ex ore rostri 
ejectis ; paraphysibus indistinctis. 
