60 PROCEEDINGS OP THE AMERICAN ACADEMY. 



but one of the latter, P. elongata, with " aristis crebris (20-25), scabris, 

 insequalibus, patulis, I'ufescentibus, persistentibus, corollam et akenium 

 fequantibus," has since been found in Mexico. P. Bonplundiana, with 

 "aristis 8-10, scabris, basi paulo dilatatis, rufescentibus, corollam aequan- 

 tibus," is identified with more recent specimens from Southeastern 

 Mexico ; and P. canescens is a species with variable pappus originally 

 described as having the disk-akenes with " paleis 20-25, aristisformibus, 

 scabriusculis, inoequalibus, rufescentibus, corollam vix superantibus, per- 

 sistentibus," while the ray-akenes are with " squamulis nonnullis minutis 

 subulatis." The fourth species, P. pyymcea, has not yet been found in 

 North America. 



In 1823 Cassini ^ discussed Lorentea, Lag., stating that it is undoubt- 

 edly the same as his own Chthonia. But, though Lagasca's genus was 

 published some months before Cassini's, he clings to his own name, 

 arguing, that compared with his own, Lagasca's description is inadequate. 

 Chthonia repens,'^ based perhaps on Pectis humifusa, Swartz, and a second 

 species, C. leptocephala^^ are described ; and after some speculative 

 remarks upon the genus, Cassini says, " Nous presumons que les Pectis 

 ■pyymcea et Bonplandiana sont des Chthonia, et que les Pectis elonyata 

 et canescens sont des Gryptopetalon" 



In 1825 Cassini* discussed Pectis, restricting it to P. linifolia, L., and 

 P. punctata, Jacq., and he again emphasized the distinctions he made 

 between the genera : " Les vrais Pectis different essentiellement des 

 Chthonia et des Gryptopetalon, par I'aigrette, dont les squamellules sont 

 subtriquetres, subulees, cornees, parfaitement lisses ; car les squamellules 

 de I'aigrette des Chthonia sont paleiforme et dentees inferieurement, fili- 

 formes et barbellulees superieurement ; et celles des Cryptopetalon sont 

 filiformes et barbellulees d'un bout a I'autre." 



Torrey's P. anyustifolia, described in 1828,^ was the first species of 

 Pectis recognized without awns, pales, or setae. The original form with 

 a squamellose crown is not, however, constant, for there are sometimes 

 present one or two slender awns. 



In 1830 Lessiug ^ took up the name Lorentea, and applied it to a group 

 very different from that of Lagasca. The characters as given by Lessing 



1 Cass, in Diet. S(!i. Nat. xxvii. (1823) 202-207. 



2 Cass. 1. c. 204. 



3 Cass. 1. c. 206. 



4 1. c. xxxviii. (1825) 202, ?,03. 



5 Torr. Ann. Lye. N. Y. ii, 214. 

 •> Linnaja, v. 135. 



