OF ARTS AND SCIENCES. 



285 



fl. March and April. — Heads 5-10 inches high, 2| -4 in diameter; 

 upper radial spines i, lateral and lower ones f - 1 inch long ; central 

 spines hardly longer, or the lower sometimes 14 - 2^ inches long. 

 Flowers 2-3 inches long, profusely covering the plant for four or 

 six weeks. Seed the largest of any Echinocerei known to me, 0.8 

 -0.9 of a line long. 



20. C. RcEMERi, E. in PI. Lindh. 1850 : ovatus, csespitosus, Icete viri- 

 dis ; costis 7-9 tuberculatis interruptis ; areolis orbiculatis, junioribus 

 breviter tomentosis ; aculeis teretibus robustis albidis sen junioribus 

 flavidulis demum cinereis, radialibus sub-8, centrali singulo robustiore 

 porrecto; floribus lateralibus infundibuliformibus limbo erectiusculo ; 

 pulvillis ovarii tubique 16-18 albo-tomentosis aculeolos 3-5 geren- 

 tibus ; sepalis interioribus 7-8 ovato-oblongis carinatis obtusis mu- 

 cronatis ; petalis 9-12 obovato-spathulatis obtusis integris concavis 

 rigidis suberectis ; stylo longe supra stamina albida sursum rosea ex- 

 serto ; stigmatibus 6-7 petala Eequantibus erecto-patulis viridibus acu- 

 tiusculis. 



In the granitic region about the Llano River, Western Texas : fl. 

 May : fruit unknown. — Often 5-12 from the same base, densely 

 csespitose ; single heads 3-4 inches high, 2 - 2J- in diameter ; areolce 

 6-8 lines apart ; radial spines 5-12 lines long, upper ones usually 

 a little shorter than the rest ; central spine 10- 15 lines long. Flower 

 2 inches long and only one in diameter, remaining open day and 

 night for a whole week, if the weather is not too warm. — Allied to 

 the last species ; but distinct by the shorter heads, fewer ribs, fewer 

 and paler spines, and smaller flower, with less numerous parts. 



21..? C. PAUCisPiNUs, E.in B. C. R. : ovato-cylindricus, parce ramo- 

 sus vel simplex, 5- 7-costatus ; areolis remotis ; aculeis robustis 3-6 

 radiantibus fuscatis, centrali nullo vel raro robusto subangulato. 



Western Texas, from the San Pedro to the mouth of the Pecos. — 

 Stem 5-9 inches high, 2 - 3 in diameter ; spines 9-16 lines long, 

 dark-colored, the central one almost always wanting. Flower and 

 fruit unknown. 



22. .'' C. HEXAEDRTJS, E. & B. in P. R. R. : ovatus subsimplex, 6- 

 costatus ; areolis remotis ; aculeis rectis rigidis tenuibus angulatis, ra- 

 dialibus 5-7 flavo-rubellis, inferiore breviore, centrali pauUo robusti- 

 ore (juniore fuscato) ssepe deficiente. 



Near Zuni, in Western New Mexico. — Heads few in each plant, 

 or single, 4-6 inches high, 2-2^ inches in diameter. Radial spines 



