936 CONTRIBUTIONS FEOM THE NATIONAL HERBARIUM. 



pubescent when young; spines usually 6 to 9, divided into two classes, the 3 

 upper spines elongate, 4 to 8 cm. long, erect or ascending, flexible, rather thin 

 but not very broad, yellowish to brownish ; lower spines spreading, weak-subu- 

 late, 5 to 15 mm. long ; flowers 2.5 cm. long ; outer perianth segments oblong, 

 acuminate ; inner perianth segments oblong, acute or obtuse ; scales on the 

 flower tube oblong, acuminate ; scales on the ovary broadly ovate, acute to 

 acuminate, very thin, more or less papery, early deciduous. 



4. Echinofossulocactus wipperm.annii (Miihlenpf.) Britt. & Rose, Cactaceae 



3: 111. 1922. 



Echinocactiis icippermannii Miihlenpf. Allg. Gartenz. 14: 370. 1846. 



Hidalgo. ^ 



Simple, obovoid, 15 cm. high, 5 to 6 cm. in diameter, dull green ; ribs 35 to 

 40, compressed, slightly undulate; areoles 12 mm. apart, hairy when young, 

 glabrate in age; radial spines 18 to 22, setaceous, white, 15 mm. long; central 

 spines 3 or 4, erect, elongate, 2 to 5 cm. long, subulate, terete, blackish ; 

 flowers 1.5 mm. long, dull yellow. 



5. Echinofossulocactus heteracanthus (Muhlenpf.) Britt. & Rose, Cactaceae 



3: 112. 1922. 



Echinocactus heteracanthus Miihlenpf. Allg. Gartenz. 13: 345. 1845. 



Echinocactus tetraxiphus Otto; Sebum. Gesamtb. Kakt. 363. 1898. 



Hidalgo, the tjT)e from Real del Monte. 



Globose to short-cylindric, light green, nearly hidden by the closely set 

 spines ; ribs 30 to 34, much compressed, somewhat undulate ; areoles white, 

 hairy when young; radial spines 11 to 13 (16 to 18, according to Schumann), 

 acicular, white, spreading; central spines 4, brownish to flesh-colored, more 

 or less annulate, compressed; flowers greenish yellow (according to Schu- 

 mann). 



6. Echinofossulocactus albatus (Dietr.) Britt. & Rose, Cactaceae 3: 112. 1922. 

 Echinocactus albatus Dietr. Allg. Gartenz. 14: 170. 1846. 



Mexico, but range not known. 



Simple, depressed-globose, 10 to 12 cm. in diameter, glaucous, the apex cov- 

 ered with spines ; ribs about 35, flat, undulate ; spines yellowish white ; radial 

 spines 10, setaceous, 1 cm. long; central spines 4, the uppermost flat and an- 

 nulate, the central terete, porrect; flowers white, 2 em. long. 



7. EcMnofossulocactus lloydii Britt. & Rose, Cactaceae 3: 113. 1922. 

 Zacatecas. 



Nearly globular, 12 cm. in diameter or more, crowned by the long over- 

 topping connivent spines ; ribs very numerous, thin, more or less folded ; are- 

 oles brown, woolly when young ; radial spines acicular, 10 to 15, white, 2 to 

 8 mm. long, spreading; central spines 3, light brown, much elongate, some- 

 what incurved and connivent, the two lateral ones similar and not so papery, 

 the middle one very thin, annulate, 4 to 9 cm. long; flowers small, nearly 

 white ; outer perianth segments with a green stripe on the midvein ; inner peri- 

 anth segments thin, narrowly oblong, acute; scales on the ovary ovate, acute, 

 very thin. 



8. Echinofossulocactus zacatecasensis Britt. & Rose, Cactaceae 3: 113. 1922. 



Zacatecas. 



Plants solitary, globular, 8 to 10 cm. in diameter; ribs pale green, very 

 thin, about 55 ; radial spines 10 to 12, spreading, acicular, white, 8 to 10 mm. 

 long ; central spines 3, brownish, 2 of them terete, but the middle one flattened, 



