ultimate cell is never a mucro. Oogonia aggregated, oospore 210 to 

 2I 5 lon g> 20 to 2I broad, with 7 to 8 ridges, surface peculiarly 

 marked by short elevations (see plate) ; these elevations are clearly seen 

 with moderate lenses ; they show on the edge of the spore like minute 

 mountain peaks ; they extend from the ridges at right angles a short 

 way, and are irregularly distributed over the surface, but are always 

 short. 



This species was collected by Prof. John Macoun near Niagara 

 Falls, and subsequently in Lake St. Clair. 



Explanation of Plate. Fig. I, plant natural size; Fig. 2, fertile verticil X 2 5 '> 

 Fig. 3, sterile verticil X 2 5 i Fig. 4, oospore X 5; Fig- 5, surface of oospore highly 

 magnified. 



NITELLA AXILLARIS, A. Br., Characecn aus Columbien, Guyana und 

 Mittelamerika, 1858. 



Flexible, small ; sterile verticils usually consisting of eight leaves, 

 quite simple, elongated, their apices terminating in a minute crown of 

 4-5, very short, two celled leaflets; fertile verticils contracted in mi- 

 nute, sub-sessile axillary " heads," the leaves of which are mostly twice 

 divided, the terminal segments two-celled, bearing an antheridium and 

 oogonia which are often aggregated ; coronula of the oogonium short 

 and obtuse, nucleus ovate, sub-globose, fuscus, y-striate 290-320 long ; 

 "membrane of oospore reticulated" Nordstedt. In stagnant pools 

 near Caracas, March, 1854, legit Gollmer (Herb. A. Br.). The same 

 species was collected by F. Mueller, near Orizaba, Mexico ; in this 

 form the stem is simple, or with only a few branches, about i mm, in 

 diameter; the fruiting "heads" i^ to 2 in diam., the terminal seg- 

 ments of the leaves 60 to 120 in diam. ; the mucro 40 to 50 diam. at 

 base, 100 to 120 long. A variety was collected in Java, near Batavia 

 (Herb, van den Bock.), mixed with acuminata v. Javanica and polyglo- 

 chin v. Javanaca, which varies from the American form in being more 

 delicate with smaller, more completely sessile "heads" and smaller 

 oogonia. This form carries also the minute crown of small terminal 

 leaflets on the apex of the leaves. 



The above description has been quoted from A. Braun, and the 

 figures have been copied from the Braun-Nordstedt " Fragmente." 

 The plants have not been seen by me. 



NITELLA MORONGII , Allen, Bull. Torr. Bot. Club, XIV., p. 214. 



Slender, 2 to 6 inches high ; lower verticils consisting of long 

 sterile leaves once or twice divided, terminating in a single mucronate 

 cell ; some of the sterile leaves appear to terminate in a node, as 

 though terminal cells had dropped off, but we have not been able to 



