24. 
South of the Rio Grande, Chihuahua, &c. — The var. 8. from Mon- 
terey may belong either here or to the next species. The var. y. 
from Sonora, without any central spines, and with very rigid radial 
ones, 1— 44 lines long, is not yet sufficiently known to decide about 
its affinities. 
6. C. cmspitosus, E. in Pl. Lindh. 1845: ovato-cylindricus, 12 - 
18-costatus ; areolis lanceolatis ; aculeis radialibus 20-30 rectis seu 
subrecurvis pectinatis albidis, centrali nullo vel raro, uno alterove bre- 
vissimo ; tubo floris purpurei pulvillis 80-100 aculeolos capillares 
6 — 12 obscuros lanamque longam cineream gerentibus dense stipato. 
Var. a. minor: aculeis brevioribus gracilioribus non intertextis ; 
floribus minoribus. 
Var. 8. Mason: aculeis longioribus robustioribus intertextis ; flori- 
bus majoribus. 
ar. y. CASTANEUS: aculeis rubellis seu castaneis. 
From the Canadian near Delaware Mount, to the Rio Grande, and 
south to Monterey ; west not farther than the San Pedro River: fl. in 
May and June. — This species, now not rare in cultivation, seems to 
be sufficiently distinct from the preceding, and may always be recog- 
nized by the characters indicated. 
7.? C. apustus, E. in Wisl. Rep.: ovatus, 13— 15 costatus ; areo- 
lis ovatis seu ovato-lanceolatis; aculeis radialibus 16-20 adpressis 
albidis apice adustis, lateralibus inferioribusque longioribus, summis 
setaceis brevissimis, centrali nullo seu valido porrecto atrofusco. 
Mountains west of Chihuahua : flower and fruit unknown. — Echi- 
nocereus radians, ©. is the form with stout central spines. 
8. ? C. rurispinus, E. l. c.: ovato-cylindricus, 11-costatus ; areolis 
lanceolatis ; aculeis radialibus 16-18 adpressis intertextis, lateralibus 
czteris multo longioribus fuscis recurvatis, centrali singulo valido 
fusco porrecto; flore infundibuliformi, tubo subelongato, limbo Bone 
tulo; stigmatibus 8 tenuibus albidis. 
Mountains west of Chihuahua: fl. in May.—Stem four inches 
high: radial spines 4-9 lines, central one about an inch, long. 
Flower different from that of all other Echinocerei in the length of 
the tube (over 2 inches long, and half as wide) and the whitish stig- 
mata. Seems to form a transition to other sections of the genus. 
9. ? C. uoneisetvs, E. in B.C. R.: subsimplex, ovato-cylindricus ; 
costis 11-14 tuberculatis ; areolis orbiculatis; aculeis setaceis albis, 
