II 



I 



apparent relationship to it, being similar chiefly in being dioecious and 

 having fruit enveloped in jelly. 



Explanation of Plate. Fig. I, female plant more elongated and diffused than 

 Fig. 2, a male plant more contracted ; Fig 3, male terminals x 25 ; Fig. 4, female 

 terminals x 25 ; Fig. 6, oospores x 50 ; Fig. 5, surface of same highly magnified. 



N. PR^LONGA, A. Br. Die Characeen Afrika's, Berlin, 1868 

 (name only); description in Braun-Nordstedt " Fragmenta " etc., 

 1882, with figures. (N. gelatinosa v. gigantea, Halsted, Charac. 

 Americ. p. 174, 1879). 



This species appears to be the largest known Nitella, collected by 

 Dr. Ravenel in the " Santee Canal" South Carolina, in 1853, a few 

 specimens of which exist in the collections of Engelmann (Missouri 

 Botanical Garden), Gray, at Cambridge, Mass., and of Braun, in Ber- 

 lin ; also collected by Lindheimer in Texas, summers of 1847 ar >d 

 1848, "in three creeks between the upper Guadaloupe and Pierde- 

 nales, often at a depth of ten feet." 



The stems attain a diameter of 2 to 3 mm. and a length of 

 several feet (4 to 6 or more). The internodal cells are often 6 to 8 

 inches long, the nodes bearing verticils of long sterile leaves, which 

 below are nearly as large and long as the stems, becoming smaller 

 above. The leaves are simple and terminate abruptly in a mucroni- 

 form point. Braun in his "Fragmenta " states that the young leaves 

 terminate in a cluster of minute short leaves which are not readily 

 noticed, and which fall off when old ; the accompanying cut is copied 

 from his figure. I have not observed these 

 minute terminal leaflets, partly due, perhaps, to 

 a desire to avoid mutilating the few specimens 

 I have been able to examine. From the upper 

 verticils, pedicils arise which bear verticils of 

 minute leaves which are once divided and bear 

 both antheridia and sporophydia ; the pedicil 

 abruptly diminishes as the first verticil of fertile 

 leaves appears, and from that point to the tip 



of the fruiting part the plant is enveloped in jelly; see Fig. 2. The 

 fertile verticils are usually four in number, and each consists of eight 

 leaves which are once divided ; the first segment is quite short, about 

 150 in diameter; the terminal segments, three in number, acuminate 

 and sharply pointed, overtop the fruiting organs ; there is an antheri- 

 dium and a single sporophydium at the node of each leaf. The oospore 

 is black with 6 or 7 rather prominent and sharp ridges, 500 to 560 

 long and of the same breadth ; it surface is covered, when mature, by 

 fibres, matted like felt. The antheridia are 360 in diameter. 



