CACTACER. 545 
50. Cereus polyacanthus, Engelm. in Bot. Wisliz. Exp. p. 20, sub Echinocereo. 
Trexas.—Norta Mexico, common about El Paso and thence to the mountains of 
Chihuahua (Bigelow, Wislizenus, &c.). 
51. Cereus polylophus, DC. Rev. Cact. p. 115. 
Pilocereus polylophus, Salm Dyck, Cact. ed. 2, p. 184. 
SoutH Mexico, without locality (Coulter), Mestitlan, Zimapan, Las Ajuntas, and on 
the Zopata at Tlacolula (Ehrenberg). 
52. Cereus pottsii, Salm Dyck, Cact. ed. 2, p. 208. 
Norra Mexico, Chihuahua (Potts). 
53. Cereus pterogonus, Lem. Cact. Gen. et Sp. Nov. Hort. Monv. p. 59. 
Mexico. Hort. Kew. 
54, Cereus pulchellus, Pfeiff. Enum. p. 74. 
Echinocactus pulchellus, Mart. in Nov. Act. Nat. Cur. xvi. pt. 1, p. 342, t. 28. fig. 2. 
Soorn Mexico, plains of Pachuca, 7500 feet (Ehrenberg, Karwinski). 
55. Cereus quadrangulispinus, Lem., ex Ehrenb. in Linnea, xix. p. 363. 
SoutH Mexico, Mestitlan, Ismiquilpan, Zimapan, &c. (Lhrenberg). 
56. Cereus ramosus, Karw. in Pfeiff. Enum. p. 108. 
MEXIco. 
57. Cereus reductus, DC. Prodr. iii. p. 463; Bot. Mag. t. 4443. 
Cactus nobilis, Haw. Synops. p. 174. 
Gymnocalycium reductum, Pfeiff. in Pfeiff. & Otto Abbild. i. t. 12. 
Mexico; GUATEMALA. 
58. Cereus rigidispinus, Miihlpf. in Otto & Dietr. Allg. Gartz. xvi. p. 12; 
Walp. Ann. ii. p. 684. 
Mexico ? 
59. Cereus rigidispinus, Lem. Hort. Univ. 1840, p. 223, t. 1. 
MEXxIco. 
60. Cereus rostratus, Lem. Cact. Alig. Nov. p. 40. 
Cereus hematus, Scheidw.? Walp. Rep. 1. p. 339. 
Mexico. Hort. Kew. 
61. Cereus rufispinus, Engelm. Mem. Tour in N. Mex. p. 104, ex Salm Dyck, 
Cact. ed. 2, p. 193. 
NortH Mexico, mountains west of Chihuahua (ex Engelmann). 
62. Cereus (Echinocereus) salm-dyckianus, Scheer in Seem. Bot. Voy. 
‘Herald,’ p. 291. 
Nort Mexico, near Chihuahua (Potts). Hort. Kew. 
BIOL. CENT.-AMER., Bot. Vol. 1, August 1880. . 4a 
