412 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
of each other. In fact, a considerable number of specimens collected 
by Dr. Edward Palmer and Dr. J. N. Rose had been distributed 
under another manuscript name given by the writer in honor of the 
latter. Of the earlier collections by other botanists some were 
distributed as Cheilanthes microphylla Swartz and others as Pellaea 
seemannt Hook. The resemblance of Pellaea arsenii to certain states 
of the former species is rather pronounced; but it bears little likeness 
to P. seemanm, with which, however, it apparently often grows 
immixed. 
The following specimens, all from Mexico, are in the U.S. National 
Herbarium: 
Feperav Districr: Valley of Mexico, Schaffner 96, 97. Near Guadelupe, Rose 
& Painter 6531. Near Tlalpam, Rose & Painter 6463, 9463, 11039. Lava 
fields near Tlalpam, Pringle 9284, 11271. 
QurERETARO: Near San Juan del Rio, Rose, Painter d& Rose, 9505. Near Querétaro, 
Rose & Rose 11177. . 
Jatisco: Near Chapala, Rose & Painter 7668. Rio Blanco, Edw. Palmer 732 
in 1886. 
Duranoo: Otinapa, Edw. Palmer 356 in 1906. Tejamén, Edw. Palmer 507 in 
1906. Vicinity of Durango, Edw. Palmer 551 in part, 887, 888, all in 1896. 
CurauaHua: Dry rocky slopes, Sierra Madre, Pringle 1443. Without special 
locality, Hdw. Palmer 87 in 1885. 
Oaxaca: Near San Luis Tultitlanapa, Puebla, near Oaxaca, Purpus 3148. 
San Luis Potosi: San Luis Potosf, Parry & Palmer 979. 
A NEW PSILOGRAMME FROM PORTO RICO. 
Among a small collection of ferns received from Porto Rico not 
long ago is the following undescribed species of Psilogramme, a genus 
not reported hitherto from the West Indies. 
Psilogramme portoricensis Maxon, sp. nov. PLATE 15. 
Plants small, not more than 7 or 8 cm. high. Rhizome erect, about 8 mm. high, 
5 mm. in diameter, coarsely radicose below, the apex bearing numerous straight, 
turgid, sharply acicular, dark castaneous, 12 to 18-celled hairs 1.5 to 2 mm. long; 
fronds 6 or 8, erect or ascending, arcuate or subflexuose, long-stipitate, 5 to 7 cm. long; 
stipe 2.5 to 3.5 cm. long, 0.5 to 0.8 mm. thick, dark castaneous, convex dorsally, 
deeply sulcate ventrally, at the base bearing a few hairs like those of the rhizome, 
above this densely hispid with flaccid few-celled simple yellowish brown hairs, these 
subpersistent; lamina lanceolate, acuminate, 2.5 to 3.5 cm. long, 9 to 14 mm. broad 
in the lower half, subbipinnate in the basal part, the dark rachis clothed like the stipe, 
the rigidly herbaceous segments strongly hispid upon both surfaces with greenish 
stramineous, stiffish, flattish, spreading, few-celled hairs; pinnz about 7 to 9 pairs 
below the acuminate simply lobate apex, the lowermost 2 or 3 pairs deltoid, ternately 
divided, the two basal segments nearly free, orbicular-obcordate, crenate, the terminal 
segment larger, asymmetrical, irregularly lobed, the lobes crenate; upper pinne 
asymmetrical, broadly oblong to suborbicular, with a single rounded adnate basal 
auricle upon the distal side, or the uppermost ones simple; veins dichotomous, 2 to 
6 ultimate branches to each segment, terminating far from the margin, sporangiate 
nearly throughout their length, the sori thus linear, confluent at maturity and partially 
concealed by the widely concave margins of the segments; spores triplanate, rounded- 
triangular, granulate, with a single wide smooth wing; anhulus consisting of 18 or 19 
cells. 
