37 
Var. a. NIGRICANS: aculeis brevioribus acute angulatis et nigri- 
cantibus. 
Var. 8. BRUNNEA: pulvillis remotioribus ; aculeis longioribus obtuse 
angulatis brunneis sursum albidis. 
Var. y. Mason: suborbiculata; pulvillis remotis; aculeis breviori- 
bus paucioribus pallidioribus. 
ew Mexico: fl. May. Var. a. is found on the Rio Grande near 
Santa Fé; @. in similar sandy locations near E] Paso; and y. in 
mountainous regions near Santa Fé. — Joints 4~ 6, or in y. even 8, 
inches long; spines mostly 1-2 inches in length. Flower about 2 
inches in diameter, with a short ovary. Fruit 1}~1} inches long, 
slender, much contracted at base so as to appear almost stipitate. 
O. Mosavensis, E. & B, in P. R. R.: prostrata; articulis grandi- 
bus suborbiculatis; pulvillis remotis ; setis fulvis; aculeis 3-6 validis 
infra fuscis. 
On the Mojave, west of the Colorado. — The material is too scanty 
to make out where it belongs; but perhaps it is only a form of 
O. pheacantha. 
11. O. Camancuica, E. & B. in P. R. R.: prostrata; articulis 
adscendentibus majusculis suborbiculatis ; pulvillis remotis plerisque 
armatis ; setis stramineis fulvisve parcis; aculeis 1-3 compressis 
fuscis apice pallidioribus, superioribus elongatis suberectis, ceteris 
deflexis ; bacca ovata late umbilicata; seminibus majusculis angu- 
latis hilo excisis. 
Llano Estacado, on the Upper Canadian River. A large, exten- 
sively spreading plant; the joints 6 —7 inches long ; spines 14-2 or 
even 3 inches long. Fruit large, juicy. Seeds 2-3 lines in diame- 
ter, very irregular and deeply notched at the hilum. 
12. O. rortispina, E. & B. 1. c.: prostrata ; articulis adscendenti- 
bus majusculis suborbiculatis ; pulvillis subremotis ; setis stramineis 
seu fulvis ; aculeis 3— 5 majoribus angulatis sepe tortis albidis cum 
2-4 gracilioribus ; bacca ovata late umbilicata ; seminibus majuscu- 
lis orbiculatis. 
On the Camanche plains, east of the elevated plateau of the Llano 
Estacado. — Similar in size and habit to the last species, its western 
neighbor, with more numerous spines than any other of our Opuntie 
*with juicy fruit. Seeds regular, and only very slightly notched at 
the hilum. 
