CACTACEA. 517 
165. Mamillaria pentacantha, Pfeiff. in Otto & Dietr. Allg. Gartz. viii. p. 406, 
et in Salm Dyck, Cact. ed. 2, p. 121. 
Mexico. Hort. Kew. 
166. Mamillaria persicina, Ehrb. in Otto & Dietr. Allg. Gartz. xvii. p. 250 ; 
Walp. Ann. ii. p. 675. 
Mexico. Hort. Kew. 
167. Mamillaria pfeifferiana, Vriese in Tijdschrift Nat. Gesch. vi. p. 51, t.1. 
fig. 2; Walp. Rep. ii. p. 303. 
Vriese distinguishes the following varieties :— 
Var. a. fulvispina, Scheidw. in Bull. Acad. Brux. vi. p. 6 (species). 
Var. 6. dichotoma, id. ibid. | 
Var. y. altissima, id. ibid. 
Var. 8. flaviceps, id. ibid. 
Var. c. variabilis, id. ibid. 
MEXICo. 
168. Mamillaria pheacantha, Lem. Cact. Gen. et Sp. Nov. Hort. Monv. p. 47. 
Mamitllaria radula, Hort. Berol. 
SoutH Mexico, on sandstone hills near Regla at 6500 feet, and at San Toro at 6000 
feet (Ehrenberg). 
169. Mamillaria pheotricha, Monv. Cat. 1846, ex Labouret, Cact. p. 39. 
Mexico ? 
170. Mamillaria phellosperma, Engel. Cact. U.S. et Mex. Bound. Surv. 
p. 6, t. 7. 
Mawmiilaria tetrancistra, Engelm. (partim) in Sill. Journ. 1852. 
Arizona.—NortH-west Mexico (Schott, Parry, Bigelow). 
171. Mamillaria phymatothele, Bergm. in Otto & Dietr. Allg. Gartz. viii. 
p. 129. 
Mexico, San Felipe (Ehrenberg). Hort. Kew. 
171*. Mamillaria picta, Meinsh. in Koch’s Wochenschr. i. p. 27. 
Mexico (Karwinski): 
172. Mamillaria plaschnickii, Otto, ex Pfeiff. Enum, p. 24. 
Soutn Mexico, near Actopan, above 6000 feet, Zimapan, Pachuca &c., at 6000 to 7500 
feet (Ehrenberg). 
172*. Mamillaria plecostigma, Meinsh. in Koch’s Wochenschr. i. p. 27. 
Mexico (Karwinski). 
