NOTES ON MYCETOZOA 163 



wall of the Mead Hook gathering is purplish and wrinkled into 

 areolae ; that from Failand is more even, and paler in colour. Both 

 of these developments differ from the Chaul End gatherings of the 

 var. lividum in the more ellipsoid sporangia, the more abundant 

 white hypothallus, and in the more rounded and smaller lime- 

 knots ; the spores are also somewhat different in having the spines 

 equally distributed over the uniformly dark surface. It is likely 

 that this species and its varieties might often be found if stackyards 

 were searched ; but the only British gatherings I had previously 

 met with were one in Berkeley's herbarium from King's Cliff, and 

 one from Hooker's herb, marked *' Purton" ; both these specimens 

 are in the Kew Collection, and had been determined by Rostafinski 

 as P. didenuoides. 



Physarum straminipes, n. sp. (PI. 886, fig. 2). On May 3rd, 

 1897, Mr. Saunders sent me a specimen of an unfamiliar Physarum 

 gathered the day before at Chaul End, near Dunstable ; and on our 

 visit to the spot on May 6th we found it in considerable abundance 

 on the damp straw. It holds a position between P. compressuui and 

 P. didermoides, but differs from both in so many points that it 

 appears necessary, in order to avoid confusion, to mark it as a 

 distinct species. The habitat is on straw, stable manure, and dead 

 leaves. Plasmodium white ; sporangia greyish white, obovoid or 

 wedge-shaped, averaging 0*7 mm. diam., single or clustered on 

 longer or shorter stalks ; or sessile, subglobose, ellipsoid, or bolster- 

 shaped on a broad base, crowded or rather scattered ; sporangium- 

 wall membranous, with dense innate clusters of white lime-granules, 

 colourless or purplish in the lower part ; stallis yellowish white or 

 straw-coloured, membranous, or somewhat cartilaginous, often 

 2 mm. long, filiform or flattened, smooth, often branched and 

 anastomosing, merging into a hypothallus of the same parchment- 

 like structure, semitransparent, and quite free from refuse-matter ; 

 columella none, or represented by a central mass of confluent lime- 

 knots ; capillitium rigid and persistent, of rather large ovoid or 

 rhomboidal lime-knots, connected by straight hyaline glass-like 

 rods, flat and broad at the junction with the knots, or terete and 

 flexuose where they spring from the sporangium-wall ; after the 

 dispersion of the spores the capillitium retains the shape of the 

 sporangia to a remarkable degree, giving the appearance, under a 

 pocket-lens, of unbroken sporangia ; the spores, as seen with 

 moderate magnification, are dark purple-brown, with a mottled 

 appearance ; high magnification shows the spore-wall to be olive- 

 brown, beset with crowded dark warts occupying broad irregular 

 patches ; these are separated from each other by nearly smooth 

 intervening spaces, having the effect of pale bands. Besides the 

 gathering near Dunstable the species has been obtained at several 

 stations within a radius of a few miles ; it was generally fojind on 

 straw, but one gathering by Mr. Crouch at PuUoxhill was on dead 

 leaves in a dry ditch. On March 11th, 1898, we found it in vast 

 abundance on stable manure round sea-kale pots in my garden at 

 Lyme Regis, Dorset. In all the gatherings the characters have been 

 constant, both as regards the shape of the sporangia, the persistent 



N 2 



