414 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 
ern Arizona the sorus invariably involves the entire inflorescence. 
It should be said that the name Ustilago filifor mis has already been 
used by Rostrup as a name for Ustilago longissima and further that 
Hennings’ specimen shows his species to be a Sorosporium and not 
an Ustilago. 
Sorosporium Syntherismae (Pk.) Fail. 
Ustilago Syntherismae Pk. (not Schw.), Ann. Rep. N. Y. St. Mus., 27: 103. 
1875. 
Sorosporium Syntherismae Earl., Host Index N. A. Fungi, 152. 1891. 
Sorosporium Cenchri P. Ilenn., Hedvv., 35 : 221, 222. 1890. 
Exsiccati: Sorosporium Syntherismae (Pk.) Far]., on Cenchrus tribuloides, 
Seym. & Earle, Econ. Fungi, 60, Same, Clinton Ust. Supp., C 39, on Pani- 
cum capillare , Seym. & Earle, Econ. Fungi, 398, Fungi Col., 1785, on 
Panicum proliferum , Ell. & Ev., Fungi Col., 1786, Seym. & Earle, Econ. 
Fungi, Clinton Ust. Supp., C 40; Ustilago Rabenhorstiana , on Panicum 
proliferum, Ell. & Ev., Fungi Col., 748, on Panicum sp., Syd., Ust., 103 ; 
Ustilago Syntherismae Schvv., on Cenchrus tribuloides , Ell. & Ev., N. A. 
Fungi, 1890a, Ell. & Ev., Fungi Col., 640, Griff., West Amer. Fungi, 30, 
on Panicum proliferum, Kell., Ohio Fungi, 41 ; Ustilago Panici-miliacei 
(Pers.), on Panicum capillare, Ell. & Ev., N. A. Fungi, 2260b, on Panicum 
sp., Ell. & Ev., N. A. Fungi, 2200a. 
Sori involving entire inflorescence, elongated, 3-7 cm. in length, 
or rarely limited to individual spikelets and then shorter, protected 
by leaf sheaths, provided with false membrane that ruptures from 
apex down disclosing black brown spore mass and shredded fila¬ 
ments of plant tissue; sterile cells of membrane hyaline, oblong to 
cubical or subspherieal, with tendency to adhere in filaments when 
separated; spore balls rather evanescent, variable in shape and size, 
irregularly oblong to subspherieal, 40—100 p in length ; spores very 
minutely verruculose, inner often appearing smooth, subspherieal or 
somewhat polyhedral to occasionally more elongated, chiefly 9-13 p 
in length. 
Hosts: Cenchrus echinatus, Mex. (Guadalajara) ; C. multiflorus, 
i\Iex.; ( . tribuloides, Conn., Colo., Ia., Ill., Ind., Ivans., Mich., 
Minn., A T eb., N. \ S. Dak., Tex., Wise.; Cenchrus sp., Ivans., 
lex., Mex.; Panicum agrostoides , Mo.; P. capillare , la., Ind., 
Ivans., Mass., Neb., S. Dak.; P. hirticaulum, Ariz. ; P. proliferum , 
D. ( ., Ia., Ill., Ivans., Mq., N. Car.; Panicum sp., Ivans., Mo. 
hiom an examination of the very poor specimen in the Schwei- 
