274 PROCEEDINGS OF THE AMERICAN ACADEMY 



Var. y. BKEVispiNUS : aculeis gracilioribus radiallbus 8-11, cen- 

 tralibus 4 teretibus cum infimo hamato radiales vix superantibus. 



East pf El Paso, near the Pecos and San Pedro Rivers, and 

 along the middle course of the Rio Grande : var. a. south of the Rio 

 Grande. Fl. July and August. — Plants from | - 2 feet high ; the 

 larger ones ovate ; areolae distant ; spines very different in size, in the 

 different varieties ; radial spines 1 - 3|, central spines 1| - 6| inches 

 long ; flowers 2| - 3| inches long ; seeds similar to the last, but with 

 much larger pits. 



§ 2. Cornigeri. 

 A. Heter acanthi. 



9. E. WisLizENi, E. in Wisl. Rep. : giganteus, globoso-ovatus ; 

 costis 21 compressis crenatis ; areolis elongatis ; aculeis radialibus 

 summis infimisque 6 robustis rectis seu curvatis, lateralibus 14 - 20 

 (additis subinde summis brevioribus fasciculatis) tenuibus elongatis 

 flexuosis ; centralibus 4 robustis angulatis annulatis rubellis, 3 supe- 

 rioribus rectis, inferiore canaliculato deorsum hamato ; floribus flavis ; 

 bacca ovata squamosissima ; seminibus reticulatis. 



Valley of the Rio Grande about El Paso, and thence to the Upper 

 Gila : fl. July and August. — Plant 2-4 feet high ; diameter smaller ; 

 radial spines 1-2, central ones 1^-3 inches long. Flowers 2^ 

 inches long. 



10. E. Lecontei, E. in P. R. R. : giganteus, obovato-clavifor- 

 mis ; costis 20 - 30 compressis crenatis ; areolis elongatis ; aculeis 

 radialibus summis infimisque 6-10 robustis angulatis plus minus 

 curvatis, lateralibus 10 - 16 (addidis subinde summis brevioribus fas- 

 ciculatis) tenuibus elongatis flexuosis, centralibus 4 robustis com- 

 pressis annulatis cornels, 3 superioribus sursum inferiore subinde 

 subhamato deorsum curvatis ; floribus flavis ; bacca ovata squamosa ; 

 seminibus scrobiculatis. 



On the lower parts of the Gila and Colorado Rivers, and in Sonora : 

 fl. August and September. Very similar to the last, but a more slen- 

 der, often quite clavate plant ; larger specimens 3-4 feet high, and 

 of only one third that diameter ; arrangement of spines similar, but 

 generally 5 (not 3) radial spines below the lowest central one ; cen- 

 tral spines more compressed, upper ones curved, lower one rarely 

 somewhat hooked ; flower, fruit, and seed smaller ; seed more ob- 

 long and pitted. 



