504 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 
Acrasis van Tieghem, 1880. 
Bull, cle la soc. bot. de France, t. 27, p. 317, 1880. 
Spores concatenate, terminating an erect simple filament consist¬ 
ing of a single row of superposed cells. 
Acrasis granulata van Tieghem. ' 
Bull, de la soc. bot. de France, t. 27, p. 317, 1880. 
Spores spherical, with a slightly roughened or granular wall, hav¬ 
ing a cuticularized external portion of deep violet color; 10 /a-15 fx 
in diameter, often unequal in the same chain, the chain varying 
much in the number of component spores and cells. 
On a culture of beer yeast. France. 
This species also is known only from the original description. 
Although the writer has made many cultures of all sorts of brewery 
products, the form has not been found. 
Van Tieghem has noted in his article on this organism that luxuri¬ 
ant conditions sometimes yield fructifications in which several stalks 
are intimately united so that a colony is formed which, with the 
exception of the blackish color, resembles a Coremium. 
Dictyostelium Brefeld, 1869. 
Plates 6, 7, 8. 
Sori stalked ; the stalk simple or only occasionally bearing irreg¬ 
ularly disposed branches ; luxuriant fructifications frequently gre¬ 
garious. Sori spherical, or subglobose. 
Dictyostelium mucoroides Brefeld. Plate 8, fig. 107. 
Abh. d. Senck. nat. ges., bd. 7, p. 85-107, pi. 1-3, 1869. 
Ceratopodium elegans Sorokin. 
Sorus and stalk white, or when old, yellowish; the fructifications 
vary in height from 2-3 mm. to 1 cm. or more. Spores oval or 
elongated ellipsoid, 2.4 />i-3 /u. by 4 /x-6 fi. 
On the dung of various animals, such as horse, rabbit, dog, guinea 
pig, grouse, etc. Also found on cultures of yeast, paper, fleshy fungi. 
