OF ARTS AND SCIENCES. 261 



juniorlbus solum lana laxa vestitis ; aculeis setiformibus cinereis pluri- 

 seriatis, in plantis junioribus sub 20 cequalibus lineam longis, radi- 

 antibus in tuberculis floriferis 30 - 40 undique stellato-porrectis, supe- 

 rioribus 6-8 longioribus clavatis ; floribus minimis subcentralibus. 



Var. /3. Greggii : major, tuberculis majoribus aculeis paucioribus 

 rigidioribus. 



From El Paso eastward to the San Pedro River. Var. /3. near 

 Saltillo. From | to 1| inches in diameter ; ^3. often 2 inches or even 

 more in diameter; tubercles -| - 1 line long, spines | - 1| lines long, 

 in /3. 1 - 2 lines long ; uppermost spines of each areola in the fully 

 developed plant 3 to 4 times as long as the others, and strongly clavate, 

 surrounded by long and loose wool, which, together with the upper 

 part of the long spines, breaks or falls off after fructification. Flowers 

 (and even fruits) nearly central, 3 lines in diameter, light pink. — 

 Near M. 7nicrothele, Muhlenp., which, however, has 2 central spines. 



2. M. LAsiACANTHA, E. 1. c, : parvula, simplex, globosa ; tubercu- 

 lis teretibus ; aculeis setiformibus pilosulis s. denudatis 40 - 80 pluri- 

 seriatis omnibus radiantibus ; floribus lateralibus albidis. 



On the Pecos River, in Western Texas : fl. in May. — Plant | to 1 

 or even 1-| inches high, and scarcely less in diameter; tubercles 2-3 

 lines long, spines 1| - 2| lines long. Flower whitish or very pale pink, 

 6 lines long. — M. Schiedeana, Fihrenh. seems to be similar, but is 

 much larger, and has large tubercles with woolly axillas, etc. 



§ 2. Crinitcz, Salm. 

 A. Aculeis centralibus rectis. 



3. M. PUSiLLA, DC, var. Texana, E. 1. c. : ovato-globosa, pro- 

 Hfera, csespitosa ; tuberculis teretibus axilla longe-lanatis ; aculeis 

 pluri-seriatis, extimis 30 - 50 capillaceis crispatis, interioribus 10 - 

 12 rigidioribus brevioribus albidis, intimis 5-8 longioribus rigidis 

 rectis versus apicem fuscatis ; floribus lateralibus rubellis. 



On the Rio Grande, near Eagle Pass and southward : fl. April - 

 June. — Plant 1-2 inches high ; spines 3-6 lines, flowers 7-10 

 lines, long. — Seems scarcely distinct from the well-known West In- 

 dian M. pusilla. 



B. Aculeis centralibus uno alterove uncinato. 



4. ? M. BARBATA, E. in Wisl. Rep. : aculeis radialibus biseriatis, 

 centrali singulo deorsum hamato ; floribus subcentralibus ; seminibus 

 tenuiter scrobiculatis. 



