504. CACTACER. 
20*. Mamillaria barlowii, Regel et Klein, Ind. Sem. Hort. Petrop. 1860, p. 46. 
Mexico (Kar winski). 
21. Mamillaria benekei, Ehrb. in Bot. Zeit. ii. p. 833; Salm Dyck, Cact. 
ed. 2, p. 91 (sub I. goodrichit). 
Mexico (ex Ehrenberg). 
22. Mamillaria bergenii, Ehrb. in Otto & Dietr. Allg. Gartz. xvii. P. 326. 
MEXxico. 
23. Mamillaria bergii, Mig. Comm. Phytog. iii. p. 104. 
Mamillaria seitziana, Mig. in Linnea, xii. p. 10, nec Martius. 
MEXICO. 
24, Mamillaria bicolor, Lehm. Delect. Sem. Hort. Hamb. 1830; Linnea, vi. 
Litteratur-Bericht, p. 11; Pfeiff. & Otto, Abbild. i. t. 3. 
Mamillaria eburnea, Mig. in Linnea, xii. p. 14, ex Pfeiff. Enum. p. 27. 
Mamillaria geminispina, Haw. in Philos. Mag. lxiii. p. 42, nec DC., ex Pfeiff. Enum. p. 27. 
Trxas.—Soura Mexico, between Tampico and Real del Monte (Poselyer), at an 
elevation of 4000 to 5000 feet on the declivities of the Barrancas of Mestitlan, Ismi- 
quilpan, and Zimapan, and near Cardonal (Ehrenberg). Hort. Kew. 
According to the rule of priority, Haworth’s name should be restored. DeCandolle 
(Rev. Cact. t. 3) figures a plant which he refers without doubt to Haworth’s species. 
(See under J. acanthophlegma.) 
25. Mamillaria bifurca, Ehrb. in 1 Otto & Dietr. Allg. Gartz. xviii. p. 188. 
MEXICco. 
26. Mamillaria biglandulosa, Pfeiff. in Otto & Dietr. Allg. Gartz. vi. p.274; 
Walp. Rep. ii. p. 302. 
SoutH Mexico, Zimapan, Los Bafios de Atotonilco el Grande &c., 6000 to 7500 feet 
(Ehrenberg). 
27. Mamillaria bihamata, Pfeiff. in Otto & Dietr. Allg. Gartz. vi. p. 274; 
Walp. Rep. ii, p. 298. | 
Mexico, discovered in the Plain of Apam (Ehrenberg). 
Salm Dyck reduces this to M. uncinata. 
28. Mamillaria bockii, Forst. in Otto & Dietr. Allg. Gartz. xv. p. 50. 
Mexico ? 
29. Mamillaria brevimamma, Zucc., ex Pfeiff. Enum. p. 34. 
South Mexico, near Octopan, in meadows at an elevation of more than 6000 feet, near 
Pachuca, Zimapan, Los Bafios de Atotonilco el Grande, &c. (Ehrenberg). 
