OF ARTS AND SCIENCES. 273 



Texas, from the Colorado to the Rio Grande, and westward as far 

 as the San Pedro River : fl. April to October. — It is unnecessary fur- 

 ther to describe this well-known and well-characterized species, which 

 is now frequently cultivated ; the compressed ribs, setaceous spines, 

 small red berry, and tuberculated seeds easily distinguish it from all 

 its allies. 



7. E. siNUATUS, Dietr. (1851): globosus ; costis 13 compressis 

 acutiusculis interruptis ; aculeis radialibus setaceis, 3 superioribus et 

 3 inferioribus rectiusculis fuscatis 1, lateralibus 2-6 tenuioribus albi- 

 dis flexuosis, rarissime hamatis ; centralibus 4 robustioribus, 3 supe- 

 rioribus rectis purpureo-variegatis, inferiore compresso seu canalicu- 

 lato elongate flexuoso vel hamate stramineo ; floribus magnis flavis ; 

 bacca ovata viridi ; seminibus minutissime punctatis. 



Country along the Rio Grande near Eagle Pass, and from there 

 eastward. — Intermediate between the foregoing and the next species, 

 and considered by Dr. Poselger a connecting link between them ; but 

 easily distinguished from the former by the larger size, thicker ribs, 

 flattened central spine, and by the shining, finely dotted seeds ; from 

 the latter, to which it approaches much more clasely, by the more 

 compressed and less strongly tuberculated ribs, the smaller number of 

 stigmata (8 - 12), smaller fruit, and much more finely dotted seed. — 

 Poselger considers this a variety of E. setispinus. His E. setispinus, 

 var. rohistus, has the same seeds, and no doubt also belongs here ; it 

 is said to have all the 4 central spines, and some of the radial ones, 

 hooked. E. TrecuUanus, Lab. belongs here, or perhaps to the next. 



8. E. LONGEHAMATUS, Gal.: subglobosus ; costis 13-17 obtusis 

 tuberculato-interruptis ; tuberculis breviter sulcatis ; aculeis radiali- 

 bus rigidis subteretibus, infimis summisque ternis, lateralibus 2-6 

 longioribus ; centralibus 4 robustis angulatis annulatis, quorum infimus 

 deorsum hamatus rectus seu flexuosus, additis subinde 2-4 superiori- 

 bus cum radialibus superioribus fasciculatis ; floribus magnis flavis ; 

 stigmatibus 15-18; bacca oblonga virescente squamosa ; seminibus 

 lucidis exsculptis. 



Var. a. CRASsispiNUS : aculeis robustissimis radialibus 8- 11, cen- 

 tralibus 4 angulatis, infimo flexuoso plus minus hamato. E. flexi- 

 spinus, E. in WisL RejJ. non Sahii. 



Var. /3, GRAciLisPiNus : aculeis gracilioribus 16-20, exterioribus 

 12-14, centralibus 4-8, infimo elongate hamato. E. hamatocan- 

 thus, Muhl 



VOL. III. 35 



