420 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
ILtustrations: Lehm, Noy. Act. Acad. Nat. Cur. 16!: pi. 12; Monatssch. Kak- 
teenk. 1: 32; Monatssch. Kakteenk. 4: 124, 125; Gesamtb. Kakteen f. 40; Rev. 
Hort. 1889: /. 139; 1890: /. 38, 39; Riimpl. Forst. Handb. Cact. ed. 2. f. 91, 92; 
Engl. & Prantl, Nat. Pflanzenf. 3%: pl. 2. f. 60. 
Cephalocereus swartzii ((riseb. ). 
Cereus swartzii Griseb. Fl. Brit. West Ind. 301. 1860. 
TYPE LOCALITY: Jamaica. 
DistRIBUTION: Jamaica. 
Cephalocereus urbanianus (Schum. ). 
Pilocereus urbanianus Schum. Gesamtb. Kakteen 193. 1899. 
Type Locauiry: Guadaloupe. 
DisrrisutTion: Guadaloupe. 
The following is clearly a Cephalocereus, but is known to us only from the 
description: 
PILOCEREUS SCHLUMBERGERI Weber; Schum. Gesamth. Kakteen 186, 1899. 
Type LocaLiry: Not cited. , 
Distrisution: Haiti, in the vicinity of Gonaives, according to Weber, as cited by 
Schumann, Gesamtb. Kakteen Nachtr. 66. 
Described as having 13 ribs, and clearly a Cephalocereus, but known to us only 
from the description. C. polygonus, from the same island, is figured as with 11 ribs, 
but without any wool. 
4. ESCONTRIA Rose, Contr. Nat. Herb. 10: 125. 1906. 
Large and much branched plants; ribs few; spines all similar, arranged in peculiar 
pectinate clusters; flowers small, yellow, tubular, one from an areole, diurnal; ovary 
globular, covered with imbricating chartaceous translucent persistent scales without 
spines or hairs; petals erect, narrow; stamens and style included; fruit globular, scaly, 
purple, fleshy, edible; seeds numerous, black. 
Type species Cereus chiotilla Weber. 
Only one species is known. 
Escontria chiotilla (Weber) Rose, Contr. Nat. Herb. 10: 126. 1906. Puarx LXV, 
Cereus chidtilla Weber; Schum. Gesamtb. Kakteen 83. 1899, ‘ 
TYPE LocaLity: ‘‘Oajaca.’’ 
DisrriputTion: Oaxaca, Mexico. 
ILLusrraTiIons: Rose, loc. cit. pl. 439A. 
EXPLANATION OF PLATE LX V.—From a photograph taken by Dr. D. T. MacDougal. 
5. PACHYCEREUS gen. nov. 
Usually very large plants, more or less branched from a definite trunk; flowers 
diurnal (?), witha rather short tube; petals short, spatulate; stamens included, numer- 
ous, inserted along the throat; style included; ovary and tube covered with small 
bracts and woolly hairs and bristles; fruit large, bur-like, dry, densely covered with 
clusters of deciduous spines and bristles; seeds large and black. 
Type species Cereus pringlet S. Wats. 
This was made a subgenus by A. Berger, whose name we have adopted. 
Pachycereus calvus (lHngelm. ). 
Cereus calvus Kngelm.; Coult. Contr. Nat. Herb. 3: 409. 1896. 
Tyre Locatiry: ‘From Cape San Lucas northward,’’ Lower California. 
Disrripution: Southern Lower California. 
