1922] ARTHUR—UREDINALES 59 
In the following list nos. 6, 8, 14, 18, 19, 20, 30-36, thirteen in 
all (that is, 30 per cent) are short cycle species, while the others 
drop into various categories of long cycle species, five ofthem, nos. 
I, 17, 23, 26, and 28, being actually or potentially heteroecious. 
Altogether the list embraces forty-three species of rusts, under 
sixteen genera, an excellent beginning to the study of the Uredinales 
of Trinidad and its adjacent islands. 
For those species which have received treatment in the seventh 
volume of the North American Flora reference is made to the page 
where the description and synonomy occur; for the other species 
reference is given to the place of the original description. Thanks 
are especially due to Dr. THAXTER and Mr. Rorer for the drawing 
and photographs included in this paper, illustrating two of the 
new ieee 
. COLEOsporIUM IpoMOEAE (Schw.) Burr. N.A.F. 87.—On 
rf es glabra (Aubl.) Choisy, St. Anns Valley, February 1913, 
II, Thaxter 4. 
Somewhat common throughout the West Indies in its uredinial stage. 
2. PHAKopsoRA Crotonis (Cooke) Arth. N.A.F. 104.—On 
Croton gossypifolium Vahl, La Seiva Valley, May 5, 1913, II, 
Thaxter 43. 
3. PHakopsora Vitis (Thiim.) Sydow, N.A.F. 102 (Uredo Vitis 
Thiim.).—On cultivated grape (Vitis sp.), Port of Spain, October 
1916, II, Rorer. 
4. CEROTELIUM Fici (Cast.) Arth. Bull. Torr. Bot. Club 44: 509. 
1917.—On Ficus radula Willd., Maraval Valley, May 14, 1913, II, 
Thaxter. 
5. Cerotelium minutum, sp. nov. 
II. Uredinia hypophyllous, more or less grouped on discolored 
spots, hidden in the pubescence of the host, small, o.1-0.3 mm. in 
diameter, soon naked, pulverulent, pale yellow becoming color- 
less; peridium and paraphyses wanting; urediniospores obovoid 
or globoid, small, 14-16 X17-23 4; wall pale yellow or colorless, 
thin, rw or less, sparingly and prominently echinulate, the pores 
obscure. 
III. Telia hypophyllous, hidden by the pubescence, minute, 
°.03-0.08 mm. in diameter, erumpent, forming columns about 
