Arthur: Uredixales of Porto Rico 
173 
The species was previously known on P. alba L. from Guade- 
loupe, and on P. rubra L., from Cuba. 
Family : Uredinaceae (Melampsoraceae) 
4. Physopella Vitis (Thiim.) Arth. Result Sci. Congr. Bot. 
Vienne 338. 1906. 
Uredo Vitis Thiim. Pilze Weinst. 182. 1878. 
Uredo Vialae Lagerh. Compt. Rend. Acad. Sci. Paris no: 
729. 1890. 
Phakopsora Vitis Sydow, Hedwigia Beibl. 38: 141. 1899. 
On Vitaceae: 
Vitis vinifera L., Pastillo Springs, Nov. 10, 571^ ; IMaya- 
giiez, Dec. 26, 6304, Jan. 5, 1914, 6731. 
Until full life history is known any generic assignment of 
species must generally remain somewhat doubtful. The only 
question involved in making the record in the present instance is 
whether or not this species, which was the type of the genus 
Physopella, differs sufficiently in important characters to keep it 
out of the earlier genus Phakopsora, to which it is assigned in 
Sydow’s Monog. Uredinearum (3: 410. 1914). Phakopsora 
has a similar telial sorus, but the uredinial sorus, according to 
IMagnus, Sydow, and others, for the writer has not seen suitable 
material, possesses a peridium opening by a central pore, whereas 
in the species on Vitis the uredinial sorus possesses peripheral 
free paraphyses. In no genus w'ell established by species of 
fully known life histories is such an association of characters 
known. The species on Vitis is, therefore, listed under Physo- 
pella, rather than under Phakopsora, as better representing 
present knowledge of distinctions, while at the same time dis- 
avowing assumption of relationships. This limitation of the 
generic character of Physopella, taken in connection with other 
information brought to light since the establishment of Physopella 
as a genus in 1906, throws out all species that are listed under the 
genus in the N. Am. Flora, except the type. 
So far the species in the West Indies has only been found on 
the cultivated grape, and only in the uredinial stage. It has 
been collected near Kingston, Jamaica, by G. von Lagerheim in 
