Differs from var. deserti in its more robust and branching habit (becoming 12.5 cm. tall and 10 cm. in diameter), shorter and thicker tubercles, more numerous (12 to 14 centrals) stouter and longer (12 to 22 mm.) spines, all of which are black-tipped (the centrals black half way down, shading into red), and pink flowers. Type, Alverson's specimens in Herb. Mo. Bot. Gard. and in Herb. Coulter. In the desert region of extreme southeastern California. Specimens examined: Southern California (A. H. Alverson of 1892): also growing in Mo. Bot. Gard. 1893. The covering of stout bushy interlocking spines is like that of var. deserti, but the black and reddish coloration gives a decidedly different appearance. On account of this appearance of a reddish-black brush the plant has been popularly called "foxtail cactus." The decidedly pink flowers were sent by Mr. S. B. Parish from specimens growing in cultivation in San Diego, and are not from the original collection of Mr. Alverson. 64. Cactus macromeris (Engelm.) Kuntze Rev. Gen. Pl. 260 (1891). Mamillaria macromeris Engelm. Wisliz. Rep. 13 (1848). Mamillaria heteromorpha Scheer in Salm. Cact. Hort. Dyck. 128 (1850). Mamillaria dactylithele Labouret, Monogr. Cact. 146 (1858). Ovate or cylindrical, 5 to 10 cm. high, simple or branching from the base and at length cespitose: tubercles large, loose and spreading, from a dilated base, more or less elongated (12 to 30 mm.) and teretish (often incurved), the groove absent in young plants and never reaching the axil: radial spines 10 to 17, slender and terete, or stouter and often angled, spreading, 12 to 40 mm. long, whitish (or more or less rose-colored when young), straight or a little curved; central spines 4 (or fewer in young plants or even wanting), spreading, 25 to 55 mm. long, stouter, bulbous at base, mostly black (the lowest the longest and stoutest), straight or sometimes curved or twisted: flowers 6 to 7.5 cm. long and of same diameter, deep red to purple: fruit ovate-subglobose, green, 15 to 25 mm, long: seeds globose-obovate, yellow, and smooth. 1.2 to 1.6 mm. long. (Ill. Cact. Mex. Bound. t. 14 and 15) Type, Wislizenus of 1846 in Herb. Mo. Bot. Gard. Mostly in loose sand, in the valley of the Rio Grande (on both sides of the river), from southern New Mexico to Eagle Pass, Texas, and doubtless further down. Specimens examined: New Mexico (Wislizenus of 1846; Wright 384, 531, of 1852; G. R. Vasey of 1881): Texas (Wright of 1850, 1851, 1852; Bigelow of 1852): Chihuahua (Evans of 1891; Budd of 1891): also growing in Mo. Bot. Gard. 1893.