1889.] NEW-YORK MICROSCOPICAL SOCIETY. 97 



appear to be extremely local, but as these plants are but little 

 studied by collectors, it is not safe to assert that this is actually 

 the case. Five of our species are also natives of the Old 

 World, three being of general sub-tropical distribution and 

 two of circumboreal range. 



Two species by recent American authors referred to this 

 genus {E. pygmcca, Torr. and E. pauciflora, Link) are remanded 

 to Scirpus where they originated as Scirpus nanus, Spreng. and 

 S. paucifloi-us, Lightf. The one is a denizen of salt marshes on 

 both sides of the continent, occurring also in similar situations 

 in the Old World, and the other is a high mountain and arctic 

 plant, also common to both hemispheres. 



My studies on the genus, which have been extended over 

 several years, have been most pleasantly facilitated by the kind- 

 ness and courtesy of Mr. C. B. Clarke, F. L. S., of the Royal 

 Herbarium at Kew, who is now engaged in monographing the 

 order Cyperace?e for the " Monographiae Phanerogamorum," 

 edited by the immortal DeCandolles. I have had the pleasure 

 of much personal consultation with Mr. Clarke, and he has 

 further favored me with numerous letters and notes, besides 

 giving me freely a list of the species as recognized by him. 

 The following enumeration is arranged as nearly as possible on 

 his forthcoming vvork, differing only in some points where I have 

 not been able fully to agree in his conclusions. I take this 

 opportunity of expressing to him my grateful thanks for all his 

 many favors. 



My gratitude is also due my many friends who have liberally 

 supplied me with specimens for study and examination. They 

 are almost too numerous to mention at this place, but I must 

 indicate to Professor Porter, Dr. Watson, Mr. Coville, Mr. Red- 

 field, Mr. Canby and Mr. Martindale the great advantages I 

 have derived from the study of the material at their command. 



SUB-GENUS LIMNOCHLOA. 



I. E. interstinctX (Vahl), Roem. & Schult., Syst. Veg. ii. 14S 

 (1817). 

 Scirpus interstinctus, Vahl, Enum. PI. ii. 251 (1806). 

 Scirpus planfag incus, Sw. Fl. Ind. Occ. i. 123 (1797), not of 

 Retz. 



