478 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 
parenchyma, consisting entirely of fertile cells surrounded by a 
definite cortex, ovoid to spherical, about 100-160 ^ in length; cor¬ 
tical cells reddish brown, polyhedral or cubical to oblong, often 
irregular, thin walled, moderately prominent, chiefly 10-18 y in 
length; spores hyaline to yellowish, chiefly subspherica] or poly¬ 
hedral, with thin smooth walls, about 10-14 y in diameter. 
Host: Ranunculus multifidus, Wise, (type). 
The spore balls are often so crowded in the leaf that they become 
irregular in shape. This crowding, apparently, also affects more or 
less the character of the cortical cells, which, as seen in cross sections, 
are often lacking in places, or again are more than one row deep. 
In this respect the species approaches quite closely Doassansia tiag- 
ittariae. The sori occur in both the petioles and leaf blades and 
the spores are said to germinate in situ. Davis has described their 
germination. 
Doassansia Sagittariae (West.) Fisch. 
Uredo Sagittariae West., Herb. Crypt. Beige, 1177. 1857. 
Physoderma Sagittariae Fckl., Fung. Rhen., 1549. 1865. 
Protomyces Sagittariae Fckl., Symb. Myc., 75. 1869. 
Protomyces Bizzozerianus Sacc., Myc. Yen., 889. 1876. 
Entyloma Bizzozerianum Sacc., Mich., 2 : 135. 1880. 
Doassansia Sagittariae Fisch, Ber. Deut. Bot. Ges., 2 : 405-416. 1884. 
Doassansia sagittariae forma conjluens Davis, Trans. Wise. Acad. Sci., Arts, 
Lett., 14:92. 1903. 
Exsiccati: Doassansia Sagittariae (West.) Fisch, on Sagittaria arifolia , 
Seym. & Earle, Econ. hungi Clinton Ust. Supp., C 14, on Sagittaria grami- 
nea , Seym. & Earle, Econ. Fungi Clinton Ust. Supp., C 15; Protomyces 
Sagittariae Fckl., on Sagittaria variabilis, Rab.-Wint., Fungi Eur., 2902a. 
Sori in leaves, thin, showing as distinct or somewhat merged yel¬ 
lowish oi reddish brown areas in which the spore balls form numer¬ 
ous very minute elevations; spore balls situated in either palisade 
layer or the spongy parenchyma, consisting of a distinct cortex with 
spore mass entirely filling the interior, subspherical, about 100-125 y 
in diameter; cortical cells light reddish brown, ovate to subspherical 
or irregularly polyhedral, rather thin walled, loosely adhering, promi¬ 
nent, 10-18 y in length ; spores loosely compacted, chiefly subspheri¬ 
cal or polyhedral, with moderately thick smooth wall, chiefly 
8-13 fx in diameter. 
