Part 10 (2/2)

missouriensis* (37), similis* (38), macromeris* (64).

Radials 30 to 50, capillary.

dasyacanthus* (51).

** Central spine solitary, not hooked.

+ Central spine porrect.

Radials 6 to 17.

missouriensis* (37), robustior* (39), scheerii* (40).

Radials 30 to 50, white and capillary.

dasyacanthus* (51).

++ Central spine curved downwards.

Radials 8 to 12.

sulcatus* (49).

Radials 12 to 26.

robustispinus (41), recurvatus (42), corniferus (47), scolymoides* (48).

+++ Central spine erect: Mexican.

Radials 7 or 8: central 50 mm. long.

salm-dyckia.n.u.s (43).

Radials 10 or 11: central 25 to 35 mm. long.

maculatus (52).

Radials 13 to 16.

compactus (44).

*** Central spine solitary and hooked.

brunneus (53).

**** Central spines more than one and none of them hooked.

Centrals 2: radials 6 to 20.

scheerii* (40), robustispinus (41), recurvatus (42), scolymoides* (48).

Centrals 3: radials 6 to 40.

scheerii* (40), scolymoides* (48), echinus* (50), conoideus (54), neo-mexica.n.u.s* (59), arizonicus* (60).

Centrals 4 or 5: radials 6 to 40.

scheerii* (40), scolymoides* (48), echinus* (50), conoideus (54), tuberculosus* (56), viviparus* (57), radiosus* (58), neo-mexica.n.u.s* (59). arizonicus* (60), macromeris* (64).

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