OF ARTS AND SCIENCES. 303 



scabrellis, interioribus 4-7 complanatis, inferioribus deflexis latioribus 

 supra striatis subtus carinatis, superiore triangulate erecto ; aculeis 

 exterioribus 8-10 gracilioribus undique radiantibus ; baccse pulvillis 

 setosissimis ; seminibus rostratis. 



Santa Fe and Albuquerque, on the plateaux : fl. in June and July. 

 — Dense spreading masses, with joints 1^-2 inches long; tubercles 

 6-8 lines long ; larger spines 6-15 lines long, and the broadest one 

 f - H lines wide. Flower 2 inches in diameter. Fruit yellow, 1J-- 

 If inches long, an inch in diameter, covered with 30-50 large pul- 

 villi. Seed 2^-3 lines in the longest diameter. Cotyledons mostly 

 oblique, or, as in most other Opunticc, incumbent. (The expression is 

 not etymologically correct, but I use it to designate the direction of the 

 face of the cotyledons towards the radicle.) 



30. 0. Parryi, E. in Sillim. Journ. 1852 : prostrata ; articulis ova- 

 tis basi clavatis ; tuberculis oblongo-elongatis ; setis paucis ; aculeis 

 angulatis scabris rubellis demum cinereis, interioribus sub-4 validi- 

 oribus compressis, exterioribus 4-8 divergentibus, extimis 6-10 

 gracilibus radiantibus ; bacca ovata pulvillis sub-40 setosissimis stipa- 

 ta ; seminibus erostratis. 



On the Mojave, west of the great Colorado. — Joints 2^-3 or 4 

 inches long, attenuated below and somewhat so above; tubercles 9 

 lines long ; inner spines 12- 16 lines long, and the larger ones some- 

 what flattened, but less than a line wide ; exterior spines 3 - 8 lines 

 long, in two series. Fruit 1^ inches long. Seeds about 2 lines in 

 diameter. — The original specimens of Dr. Parry were found farther 

 south, near San Felipe. He describes the joints as 4 - 8 inches long, 

 with shorter whitish spines or tubercles 6-12 lines long, and the 

 flower as greenish-yellow. The Mojave plant is nearly allied to the 

 last species, but may be distinguished by the shape of the joints, the 

 narrower, darker-colored, more numerous spines, and the smaller and 

 more regular seeds. 



31. O. Emoryi, E. in B. C. E,. : articulis cylindricis basi clavatis 

 glaucis ; tuberculis oblongo-linearibus elongatis ; setis paucis ; aculeis 

 plurimis rufis, interioribus 5 -9 validioribus triangulatis, compressis, 

 exterioribus 10-20 pluriseriatis undique radiantibus; floribus flavis 

 extus rubellis ; bacca pulvillos 35 - 50 setosissimos infcriores aculeo- 

 latos gerentibus ; seminibus valde insequalibus irregularibus. 



Arid soil, from El Paso through Sonora to the desert of the Colo- 

 rado : fl. August and September. — The stoutest species of this sec- 



