578 ARTHUR: NrEW SPECIES OF UREDINEAE 
this is probably the first rust recorded, and its endemic character 
on a shrub of one of the smaller West Indian islands, are items 
that make the study of the other stages in its life cycle, and of its 
relationship and distribution, matters of more than usual interest. 
Peridermium fructigenum sp. nov. 
Pycnia episquamous, numerous, inconspicuous, subcuti- 
cular, semicolumnar or irregular-conoidal, 48—58u in diameter by 
about 35u high; ostiolar filaments wanting. 
I. Aecia episquamous, numerous, often crowded thickly over 
the whole surface of a scale, oblong, 0.3-0.5 mm. wide by 0.7—1.5 
mm. long, often confluent, subepidermal, soon naked, dingy white 
when dry, ruptured epidermis noticeable; peridium irregularly 
convex, soon dropping away, peridial cells ellipsoid, loosely united, 
resembling the spores, but somewhat larger, rougher, and often 
compressed into irregular shapes; aeciospores broadly ellipsoid or 
obovate, rather small, 13-16 by 19-22; wall colorless, ahaha 
thick, 2-2.5u, rather bnely and closely verrucose. 
On Tsuga canadensis (L.) Carr., East Granby, Conn., June ai, 
1908, Perley Spaulding 114. The fungus gives the cones a peculiar, 
whitened appearance. It is remarkable that the rust should have 
so long escaped the attention of collectors. The elevated pycnia 
and evanescent peridium readily distinguish this species from P. 
Peckit Thiim., which occurs on the leaves of the same host. 
In the study of the genus Peridermium,* made some time ago 
by Mr. Kern and the writer, it was pointed out that the number 
of American species known, having subcuticular pycnia, was con- 
siderably less than the number of telial species known requiring 
similar aecia. This additional species helps to’ lessen the discrep- 
ancy. In accordance with the chain of reasoning there employed, 
the new form on Tsuga doubtless goes to some species of Puc- 
cintastrum, and judging from known distribution, it may be the 
aecial form of Puc. minimum (Schw.) Arth., having telia on Azalea. 
Aecidium leporinum sp. nov. 
O. Pycnia not seen. 
I. Aecia hypophyllous, gregarious in circular groups 1-3 mm 
across, crowded, on substratum scarcely thickened and little aig: 
colored, 0.2-0.4 mm. high; peridium cylindrical, erect or somewhat 
*Arthur & Kern, North American species of Peridermium. Bull. Torrey Club 33: 
403-438. 1906. 
