BRITTON AND ROSE—CEREUS AND ITS ALLIES. A417 
Cephalocereus lanuginosus (L.). 
Cactus lanuginosus L. Sp. Pl. 467. 1753. 
Cereus lanuginosus Mill. Gard. Dict. ed. 8. no. 3. 1768, as to name only. 
Cereus repandus Mill. Gard. Dict. ed. 8. no, 5, 1768. 
Pilocereus lanuginosus Riimpl. Forst. Handb. Cact. ed. 2. 672. 1886. 
Type Locauity: Island of Curacao, South America. 
This species is commonly referred to Cuba, Porto Rico, and other West Indian 
Islands, but is apparently to be excluded from our range. Recently Miss Albertina 
Lens sent plants from the type locality which are very different from any of our 
North American material. 
Cephalocereus leucocephalus (Poselg.). 
Pilocereus leucocephalus Poselg. Allg. Gartenz. 21: 126. 1853. 
Pilocereus forsteri Lem. Ill. Hortic. 13: under pl. 472. 1866. 
Pilocereus houlletii Lem. Rev. Hortic. 1862: 428. 1862. 
Cereus houlletii Berger, Ann. Rep. Mo. Bot. Gard, 16: 70, 1905. 
Type Locauity: Of P. leucocephalus, ‘‘ prope Horcasetas’’ in Sonora, Mexico; of P. 
houlletii, ‘‘ In Sonora.’’ 
DisrrRiBUTION: Sonora and southeastern Chihuahua, Mexico. 
ILLustRATIONS ® Rev. Hortic. 1862: f. 38-41; Riimpl. Forst. Handb. Cact. ed. 2. 
f. 89, 90; Lem. Cact. f. 5. 6; Pflanzenfam. 3%: f. 49. A, B. 
This species was described from cultivated specimens which were said to have 
come from ‘‘Sonora.’’ So far as we know no species of this genus has in ‘recent 
years been collected in, Sonora, but Dr. E. Palmer collected from some Cephalo- 
cereus in a barranca near Batopilas, Chihuahua, in 1885, long hair similar to that 
figured by Lemaire. This barranca runs down into Sonora. Schumann onty refers 
to a plant collected at Naulingo, between Vera Cruz and Jalapa. This is undoubtedly 
a different species. 
Cephalocereus macrocephalus Weber; Schum. Gesamtb. Kakteen 197. 1899. 
Cereus macrocephalus Berger, Ann. Rep. Mo. Bot. Gard. 16: 62. 1905. 
Type Locatity: Tehuacan, Mexico. 
Disrripution: Type locality and vicinity. 
IuLustrations: Contr. Nat. Herb. 10: pl. 43B; MacDougal, Bot. N. Am. Deserts 
pl. 18. 
Cephalocereus maxonii Rose, sp. nov. Puate LXIV. 
Plant 2 to 3 meters high, with few long branches; in mature plants the tops of the 
branches for about 30 cm. clothed with long (4 to 5 cm.) white hairs; ribs 6 to 8, 
acute, pale blue and somewhat glaucous; areoles small; spines about 10, slender, 
yellow, the central single (4 cm. long), all nearly hidden by the long white hairs; 
flowers purple, 4 em. long; ovary naked except for a few small bracts; fruits 3.5 em. 
broad, broader than high; seeds brownish, reticulated with an oblique basal hilum. 
Collected by William R. Maxon near El Rancho, Guatemala, April 4, 1905 (no. 
3769, type); and later, seeds only, by W. A. Kellerman, January 10, 1908 (no. 7061). 
Also near Salama, by Mr. Maxon (no. 3381). 
Type U. 8. National Herbarium no. 473710. 
One living specimen is growing in Washington, and flowers and fruit are preserved 
in formalin. Prints from a number of good photographs taken by Cook and Collins, 
W. A. Kellerman, H. Pittier, and- William R. Maxon have been mounted. 
EXPLANATION OF PLATE LXIV.—From a photograph taken by William R. Maxon of a plant near 
Salama. 
Cephalocereus millspaughii Britton, sp. nov. 
Stem branched, 2 to 6 meters high, 20 cm. thick at the base, the branches nearly 
erect, 8 to 12 em. thick, pale grayish green, pruinose, 8 to 13-ribbed, the ribs 
