M. 0. COOKE, NOTES ON PODISOMA. 267 



uniseptate, as in Podisoma, but at least triseptate, a difference as 

 great as between Puccinia and Triphragmium. They are not in- 

 volved in gelatine as in Podisoma. They have not been shown to 

 germinate, and produce teleutospores as in Podisoma, and they do 

 not " spread out above into a cl avarice -form mass." For all of these 

 reasons we think that the Podisoma foliicolum of Berkeley cannot 

 be retained in that genus, or amongst the Uredines, but must be 

 removed into close proximity with Coryneum amongst the Melan- 

 coniei. That it is not a good species of Coryneum is admitted, and 

 for that reason it is proposed to constitute it the type of a new 

 genus, under the name of Sarcostroma Berkeleyi. * 



The Podisoma Juniperi minor of Corda, already alluded to, has 

 by some authors, been considered identical with Podisoma foliicolum 

 of Berkeley, but Corda figures only one septum in the spores. 

 Fuckel therefore is wrong, and our " Handbook " also, in referring 

 Corda's species to Podisoma foliicolum. Oersted's testimony that 

 the Podisoma figured by Corda on juniper leaves is identical with 

 that of the stem and branches, is doubtless correct. Tulasne's 

 opinion j" that Corda's plant is not a Podisoma at all, was probably 

 founded on Corda's figure, mentally associated also with Berkeley's 

 species, under the impression that both were the same thing. 



These remarks may fitly be closed with an enumeration of the 

 species as they would stand if Oersted's observations are confirmed. 



1. PODISOMA GYMNOSPORANGIUM, Bon. 



Spermogonia — Spermatia cylindrical, obtuse. 



PERiDlA=i?cE's^e^'a cornuta. Tul. 

 On leaves of Mountain ash, &c. 



Protospores — Elliptical, uniseptate, constricted. 



Teleutospores — Obovate or elliptic, slightly curved. 

 On living Junipers, 



var. Clavipes — C. c£- P. —Peduncles of protospores clavate. 

 On living Juniperus Virginiana. [United States.] 



2. PODISOMA JUNIPERI, Fr. 



Spermogonia— Spermatia subfusiform. 



Peridi a= Rcestelia lacerata. Tul. 

 On leaves of hawthorn, &c. 



Protospores — Lanceolate, uniseptate, constricted. 



Teleutospores— Obovate or pyriform. 

 On living Junipers. 



* Sarcostroma. Erumpent. Spores septate, on very long peduncles, radi- 

 ating from a gelatinous stroma, 

 t Tulasne, Annales des Sc Nat. ser. iv. (1854), ii., p. 186. 



