CACTACES. 5 
thicker at base, very slender in the middle, and thickened again towards thé very acute point. 
Fruit about 9 lines long ; seed smaller than in the more northern form, 0.6 line in length and 
more distinctly tuberculated. : 
Mamillaria microthele, Muhlenpf., seems to be closely allied to our plant, but is distinguished 
(to judge from the descriptions) by its cespitose growth, and its distinct 1 or 2 central spines. 
No allusion is made in the descriptions to the remarkable vertical tuft, though the small pale 
rose-colored fiowers are mentioned. The name, JM. micromeris, refers to the smallness of all the 
parts of this species. 
2. M. xastacantTua (sp. nov.): parvula, simplex, globosa seu ovato-globosa ; tuberculis cylin- 
dricis lete viridibus; axillis nudis; areolis junioribus albido-lanatis ; aculeis 40-80 pluri- 
seriatis omnibus radiantibus maxime inaequalibus brevibus setiformibus albis rectis seu paullo 
recurvatis ciliato-pilosulis vel denudatis ; floribus lateralibus parvis ; sepalis 13 obtusis, exte- 
rioribus mucronatis ; petalis 13 fere uniseriatis oblongis obtusis emarginatisve ; stylo stamina 
brevia longe superante ; stigmatibus 4~5 ovatis brevibus erectis convergentibus ; bacca elongata 
clavata coccinea; seminibus numerosis obovato-subglobosis scrobiculatis nigricantibus, hilo 
basilari ovali. 
Var. a. Mivor: caule minore ovato; aculeis paucioribus brevioribus dense pilosulis. (Tab. IIT.) 
Var. 8. ‘DENUDATA: caule majore globoso ; aculeis plurimis longioribus subnudis. (Tab. IV.) 
About Leon spring and Camanche spring, west of the Pecos, on low limestone hills, among 
herbage, C. Wright: fl. April and May.—A pretty little species, covered with and almost 
entirely hidden under the innumerable soft, more or less pubescent spines. The smaller form 
is 9-12 lines high and 6-9 lines in diameter; tubercles in 8 or 13 spiral rows, 2 lines long 
and nearly 1 line in diameter ; areolw 14 line distant from one another. Spines 40-60, 1}-2 
lines long, the upper exterior ones a little longer than the rest, the innermost ones often not 
half as long as the others. The larger form, var. §, is 1-1} inch high, and of alniost the 
same diameter ; tubercles 24-3 lines long, in 13 or 21 spiral rows; spines 50-80 almost, or 
the old ones entirely naked, 14-2} lines long, the innermost usually much shorter. The flower is 
half an inch long, and, when fully open, of the same diameter ; petals white, with a red streak in 
the centre, which at base forms a red circle around the yellow stamens; style yellowish, with 
4 or 5 yellowish-green stigmata, which form together a short globose head ; fresh fruit 6-10 
lines long, without the remains of the flower, somewhat persistent and finally shrivelled up, 
greyish, obovate-clavate, deeply imbedded and hid between the tubercles ; seeds 10-25 in each 
fruit, smaller than in the last species, and altogether different in shape and surface, about 0.5 
line long, very conspicuously pitted, hard and brittle. I have named this species J. lasiacan- 
tha fromthe usually very soft pubescence of the spines. It is evidently closely allied to M. Schiedeana, 
Ehrenb.; but this isa much larger plant, with larger tubercles, very woolly axils, and its spines 
tipped by asilky brush. Both this and the last species belong to Prince Salm’s §3. Polyacanthe 
** aculeis patentissimis adpressis. The position of the flower, however, seems to indicate that they 
are widely separated from each other, though the external appearance of the plants is very 
much alike, 
3. M. pustnna, DC., var. Texana: ovato-globosa, prolifera, cespitosa; tuberculis teretibus 
versus apicem conicis, axilla longe-lanatis setosisque ; aculeis pluriseriatis, extimis numerosis- 
simis (30-50) capillaceis elongatis flexuosis vel crispatis albis, interioribus 10-12 sensim ri- 
