270 PROCEEDINGS OF THE AMERICAN ACADEMY 



29. M. MACROMERis, E. in Wisl. Rep. (M. dactylothele, Lah.) : 

 simplex s. e basi ramosa, ovata ; tuberculis magnis patulis, laxis, tenu- 

 iter ultra medium sulcatis ; aculeis tenuibus elongatis rectis s. pauUo 

 curvatis exterioribus 10 - 17 albidis, centralibus sub-4 longioribus 

 robustioribus subangulatis, fuscis s. nigricantibus ; floribus ex areolis 

 supra-axillaribus in tuberculo ipso oriundis magnis ; bacca subglo- 

 bosa viridi ; seminibus parvis Icevibus fuscis. 



In the valley of the Rio Grande, from Southern New Mexico to the 

 middle course of the river near Presidio, and even lower down : fl. 

 July and August. — A most remarkable species in many respects, 

 and forming a transition to Echinocactus, though the mamillate form 

 is so very striking. Plant 2-4 inches high ; tubercles variable, 6-8 

 or 10-12 and even 15 lines long. Radial spines ^-l^ inches 

 long ; central ones often l^- - 2^ inches in length. Axils always 

 naked. Flower springing from the lower end of the groove, which 

 runs down about two thirds of the tubercle, 2^-3 inches in diame- 

 ter, rose-colored or purple ; not rarely with a few sepaloid scales on 

 the ovary (and fruit). Seeds thick, but only 0.6 - 0.8 line long. 



Subgen. 3. Anhaloniubi. (Gen. Anhalonium, Lem. Ariocarpus, 

 Scheidio.) Flores e basi tuberculorum hornotinorum triangularium 

 subinermium vel in vertice ipso oriundi : ovarium emersum. 



30. M. FissuRATA, E. in B. C. R. : simplex, depresso-globosa s. ap- 

 planata ; tuberculis e basi applanata crassis extus infraque Isevibus, 

 supra sulco centrali Villoso lateralibusque glabris profunde quadripar- 

 titis sulcisque transversalibus superficialiter multifidis, inermibus ; 

 floribus e villo longo sericeo centralibus roseis ; baccis ovatis vircs- 

 centibus in lana densa occultis ; seminibus nigris tuberculatis. 



On the limestone hills, near the junction of the Pecos with the Rio 

 Grande : fl. October. Heads 2-4^ inches in diameter; tubercles 6 - 

 10 lines long, and a little less broad ; central longitudinal groove in the 

 very young ones bearing dense silky wool over half an inch long, 

 which by age becomes dirty and matted, and finally disappears entirely 

 in the very old ones. The lower end of the groove, which only extends 

 down as far as the rough or verrucose part of the tubercle goes (about 

 two thirds downward), bears the flower and fruit, very much like the 

 floriferous areola of the last-mentioned species. Flower about one 

 inch long and wide. Seed very roughly tuberculated, different from 

 that of any other Mamillaria examined by me, but quite similar to 

 that of other Anhalonia. 



