82 AMERICAN FERN JOURNAL 
These hairs (or more properly scales) with enlarged 
bases and attenuate tips are sparsely scattered over the 
under surface of the sterile frond. Facing in all direc- 
tions they look absurdly like infant tadpoles with their 
enlarged heads and long wavering tails. 
On El Yunque, in the luxuriant mountain palm 
forest,every stump and tree and stone was covered with 
ferns. In one slightly open spot was a lovely grove of 
tree ferns, the finest I saw anywhere. Among species I 
had not before collected were Polypodium cultratum 
Willd., Trichomanes rigidum Sw., Vittaria remota Fée, 
and a species of Pleurogramma, the latter resembling 
Vittaria, but with the sporangia down the center in- 
stead of along the margins. A beautiful Selaginella 
found in most of the wet forests was abundant here. 
Most of the Lycopodiums of Porto Rico are very dif- 
ferent from any of our species. Lycopodium reflecum 
Lam., found growing on wet rocks on Alta de Bandera, 
reminds one of L. lucidulum, but the other species, grow- 
ing high up on trees and hanging in great tassels two or 
three feet long appear strange to northern eyes. Ly- 
copodium linifolium L. and L. tazifolium Sw. have 
linear leaves half an inch to an inch long, crowded and 
imbricate in the second species. In L. aqualupianum 
Spring the crowded leaves are elliptical, about a centi- 
meter long, the slender terminal fertile branches with 
small scale-like leaves. Lycopodium setaceum Lam., a 
common species, has minute, oblique, scale-like leaves 
throughout, these lax, but resembling those of our own 
L. clavatum. 
Polystichum rhizophyllum (Sw.) Presl, with the habit 
of our walking fern, is found about mountain passes in 
the center of the island. 
On the limestone cliffs of the northern and western 
coast the ferns were mostly those with compact habit 
and more or less leathery fronds. In pockets in lime- 
