ILLUSTRATIONS. 



PLATES. 



Pacii e 



Plate \ \*1. Echinocactus robustus and Mamillaria angularis 83 



XVII. Opuntia tunicata ami Echinocactus ingi ns 83 



X VI 1 1. Piloa /•< usfulviceps 83 



XIX. I \ r< US h<>// in, i ns 



XX. Cereus stellalus B3 



XXI. ( 'en us wi beri B4 



XXII. Fouquii ria spinosa 85 



XXIII. Beaucarnea oedipus B8 



XXIV. < 'alibanus ecu spitosus 90 



X X V. Calibanus caespitosus 90 



XXVI. Potentilla lozani 95 



X X VII. Alchemilla procumbt //•-■ 96 



XXVIII. PUJiecolobium revolutum 96 



XXIX. Hoffmanseggia arida 



X XX. 11, ntkamantha pumila 99 



XXXI. Cologania tenuis LOO 



XXXII. Odonia incana L02 



XXXIII. Odonia viridiflora 103 



XXX IV. Sphinctospi rmum constrictum L07 



XXXV. Tonoxalis confusa, T. furcata, and I. jaliscana llo 



XXXVI. T ebinthus arida lis 



XXXVII. Polygala calcicola 1 '1'2 



XXXVIII. Polygala n, teoni 1 l'l? 



XXXIX. Polygala turgida Il':') 



XL. Abidilon durangt nse L23 



X LI. Wissadula lozani L24 



XLII. ( 'alceolaria humilis L25 



X LI 1 1. Esconirixx chiotilla and ( 'ephalod r< us macroi ephalus li'ii 



TEXT FIGURJ 3. 



Fi<;. 1 . Beaucarnea guatemaU nsis sv - 



2. Beaucarnea im rmis ss 



.">. Da8ylirion qaadrangulatum B9 



4. < 'alibanus in, spitosus 90 



5. Nolina altamiranoana 91 



6. Nolina < legans 91 



VII 



