OP ARTS AND SCIENCES. 275 



E. INGENS, Zucc, in the number and arrangement of spines, is 

 the simple type of our more northern species : it has on the oval 

 areolae 4 stout cruciate central spines, 3 upper and 3 lower radial 

 ones, and only 2 slender lateral spines. Seeds smooth. The flower 

 seems to refer it, however, to the Eriocarpi. 



B. HomcBacantM. 

 * Lepidocarpi. 



11. E. Emoryi, E. (in Emory's Rep. 1848, and B. C. R.) : gran- 

 dis, ovatus ; costis 13 - 20 obtusis tuberculatis ; areolis ovatis ; acu- 

 leis radialibus 7-8 suboequalibus robustis subangulatis annulatis paullo 

 recurvatis rubellis 1-2 pollicaribus, centrali singulo recurvo s. sub- 

 hamato paullo robustiore ; floribus magnis purpurascentibus. 



Lower Colorado, and principally in Sonora : fl. August and Sep- 

 tember. Larger plants 2| - 3 feet high ; spines usually 1-2, and, in 

 a large specimen from Guaymas, nearly 3 inches long. Flowers 

 about 3 inches long. Fruit unknown. 



12. E. viRiDESCENS, Nutt. : globosus, simplex seu raro ramosus ; 

 costis 13-21; aculeis robustis compressis annulatis plus minus cur- 

 vatis rubellis, radialibus 12-20 infimo breviore magis curvato ; cen- 

 tralibus 4 angulatis robustioribus longioribus, infimo rectiore longi- 

 ore ; floribus virescentibus ; bacca squamosa ; seminibus minutissime 

 scrobiculatis. 



San Diego, California. — Less than a foot in diameter, globose or 

 flattened ; radial spines 5-10 lines long, 3 upper central ones a little 

 longer, and lower central spine 12 - 18 lines long. Flower IJ- inches 

 long. 



13. E. CYLiNDRACEUs, E. in Sill. Jour. 1852 : ovatus seu subcylin- 

 dricus, plerumque e basi ramosus ; costis 21 vel pluribus ; aculeis ro- 

 bustis compressis annulatis plus minus curvatis flexuosisve rubellis, 

 radialibus sub- 12, aculeis adventitiis sub- 5 gracilioribus supra ssepe 

 adjectis, infimo hamato, centralibus 4 angulatis robustissimis cruciatis, 

 superiore latiore sursum recto, inferiore decurvato ; floribus flavis ; 

 bacca squamosa. 



San Felipe, on the eastern slope of the Californian mountains : fl. 

 in June. — The largest specimens seen were 3 feet high and one foot 

 in diameter ; the branches or young single plants are globose. Ra- 

 dial spines 1-2 inches long ; central spines 1 - 1^ lines broad, about 

 2 inches long. Similar to the last, but well distinguished by the char- 

 acters indicated. 



