526 CACTACER. 
257. Mamillaria umbrina, Ehrb. in Otto & Dietr. Allg. Gartz. 1849, p. 287. 
MExIco. 
258. Mamillaria uncinata, Zucc. in Pfeiff. Enum. p. 34; Pfeiff. et Otto, 
Abbild. i. t. 19. 
Mamillaria adunca, Scheidw. 
Mexico, meadows near Pachuca, 7500 feet, Cerro Ventoso, near Minera] del Monte, 
8500 feet (Karwinski), 
259. Mamillaria variamamma, Ehrb. in Otto & Dietr. Allg. Gartz. xvii. 
p. 242; Walp. Ann. ii. p. 675. | 
MEXIco. 
260. Mamillaria versicolor, Scheidw. in Bull. Acad. Brux. v. p. 494; Walp. 
Rep. il. p. 299. 
MEXICO. 
261. Mamillaria vetula, Mart. in Act. Nov. Nat. Cur. xvi. pt. 1, p. 338, t. 24. 
Mexico, on rocks near San José del Oro, 13,000 feet (Karwinski), chalk cliffs at 
La Encarnacion, 11,000 feet (Ehrenberg). 
262. Mamillaria villifera, Otto in Pfeiff. Enum. p. 18. 
Mexico, Oaxaca (Lhrenberg). 
263. Mamillaria virens, Scheidw. in Otto & Dietr. Allg. Gartz. ix. p. 43. 
Mexico, Oaxaca (Hhrenberg). 
264. Mamillaria viridis, Salm Dyck, Cact. ed. 2, p. 116. 
Mamillaria prelii, Mihlpf. in Otto & Dietr. Allg. Gartz. xiv. p. 372, ex Salm Dyck, loc. cit. 
MEXxIco. 
265. Mamillaria vivipara, Haw. Suppl. p. 2. 
Var. B. ned-mexicana, Engelm. Cact. U.S. et Mex. Bound. Surv. p. 16. 
Texas ; New Mexico.—Norra Mexico, Sonora (Schott). | 
A variable species, extending northward to the Upper Missouri and YELLOWSTONE 
rivers and the BLack HILis and Rocxy Mountains. 
266. Mamillaria vulpina, Ehrb. in Otto & Dietr. Allg. Gartz. xvii. p. 308; 
Walp. Ann. il. p. 678. 
Mexico. 
267. Mamillaria webbiana, Lem. Cact. Gen. et Sp. Nov. Hort. Monv. p. 45. 
Mexico, near San Toro and on the Mesa de la Magdalena (Lhrenberg). 
268. Mamillaria wegenerii, Ehrb. in Bot. Zeit. i. p. 738. 
SoutH Mexico, Oaxaca (ex Ehrenberg). 
