48 t 



Brown's Mills, N. J. — O. laeve, Wittr. Hopatcong/N. J. — O. 

 plusioporum, Wittr., Waterloo, N, J. — O clliatum, Hass, Atsion, 



O. Donnelh^ n. sp, — O. oogoniis singulis, subglobosis ; oos- 

 poris echinatis, oogonia fere complentibus, globosis, echinis con- 

 icis ; androsporangiis 4-10-cellularibus ; nannandribus bicell- 

 ularibiis, pauUulum curvatis, stipitatis, in cellulis suffultoriis sed- 



entibus. Crassit. cell, veget .0023 -.0025. Altit. 1-2-plo ma- 

 jor. Oogon .0O3"-.oo33''' ; oospor. c. echin. .oo28"-.oo3." 

 Coll. J. D. Smith, Florida, 1879. 



Bulbochaete, Ag. — B. monile, Wittr. and Lund. Hopatcong Lake, 

 N. J. 



Hormiscia. Aresch. — H. speciosa, Crouan. Brackish water near N. 

 Y. Coll. R. Hitchcock, 



Ulothrix, Ktz.— K. tenerrima, Ktz.—Coll. Dr. Hobby, Iowa. — U. 

 compacta, Ktz. Small pool, Perth Amboy, N. J. 



Microthamnion, Naeg. — M. Ktltzingianum, Naeg. Water troughs, etc. 



Stigeoclonium, Ktz.— S. irregulare, Ktz. 



Coleochaete, Breb. — C. soluta, Pringsh. Ponds, N. Jersey. Collected 

 fine specimens in various stages of development. The young 

 forms reflect upon the character of Chaetococcus^ and tell a tale 

 on forms of Aphanochaete^ and particularly on Horposteiron 

 {Aphanochaete) giobosaj Nordst. 



Chantransia, Fries. — C. macrospora, Wood. Hitherto found only in' 



S. C. The large pond at Atsion, N. J., abounds with it. Along 

 the shores, it grows on sticks, larger timbers, and the roots of 

 trees extending into the water; 



Balrachosperrnum. — B. vagum, Roth., is also frequent in the same 

 pond. 



§ 36. Note on the Differences between Cyperus ovularis, ^ 



Torr., and C. cylindricus, N. L. Britton, (with a plate.) 



In the Bulletin for August, 1879, 1 called attention to the fact that 

 Cyperus (Mariscus) cylindricus^ should be regarded as specifically 

 distinct from C. ovularis^ and not as merely a variety of the latter. 

 I take this opportunity to figure the most marked differences between 

 the two species on the accompanying plate. Fig. i is an umbel of C. 

 ovularis^ showing its dense globular heads ; (B) is a three-flowered 

 spikelet, and (A) an achenium of this species. 



Fig. 2 represents an umbel of C. cylindricus with its cylindrical 

 heads ; (D) is a two-flowered spikelet, and (C) the achenium. Fig- 

 ures 1 and 2 are the natural size; (B) and (D) are enlarged six times, 

 and (A) and (C) are enlarged twelve times. 



The specimen of Cyperus ovularis from which the figures were 

 drawn, was collected near Norfolk, Va., by Mr. H. P. Worcester ; that 

 of C cylindricus I collected myself near Manchester, N. J. 



I am indebted to Mr. Arthur Hollick for the beauty and accu- 

 racy of the drawings. 



School of Mines, N. Y., April igth, i88o. 



N. L. Brixton. 



