THE VENATION OF THE SPECIES OF SALIX. 53 



some 



inconspicuous, curving down to join the preceding primary. 

 Secondaries relatively much weaker, usually quite regular, 

 though with marked exceptions. Tertiaries thin, regular, 



forming rectangular, blocky, small meshes with scant ter- 

 minals, or in mature leaf with, simply, occasional stellate 

 points. The forms of the meshes correspond nearly with 

 the different forms of cordata, being, however, generally 



regular or smaller. The terminals 



thick texture permits. 



somewhat 



primaries 



secondaries; extends close up to the midrib. The up-curv- 

 ing and parallelism of the secondaries, as mcordata, is gen- 

 erally well marked. Veining at apex is cor da fa-like. 

 Plate 2, fig. 8. 



J. Hill 



Englewood, Illinois. 



9. S. discolor, Muhl. — Primaries rather distant, curved- 



g, dividing, forming a reg 



sending a strong vein into each tooth. The intervening 



costals curve down, ranging themselves with the secondaries 



to meet the primaries. Secondaries regular in part, in 

 which case they are close; frequently quite irregular, 

 broken, more or less zigzag. Tertiaries strong, forming 



medium-sized mesh 



terminal 



branching. Comb-like terminals along midrib. Oblitera- 



te 



tion slow. Veining as a whole strong. — Plate 2, fig. 9. 



Illustration is from specimens from Lauderdale, Wis., 

 furnished by M. S. Bebb, Esq. Examined also specimens 

 from the vicinity of Ithaca, N. Y., furnished by Prof. L. 

 H. Bailey, Cornell University. 



10. S. cordata, Muhl. — Primaries, in broad leaves, in- 

 cline to the horizontal, dividing, the arms forming arches, 

 while tipwards regular loops with round or roundish ends 

 are seen ; in narrow forms, looping often prevails through- 

 out; intervals contain one or more costals. Secondaries 



8 



