OF NAIAS GRAMINEA^ VAR. DELILEI. 



43 



centre of each fascicle the leaves are destitute of auricles^ 

 aud pass into short lanceolate bracts^ in the midst of which 

 we find the flowers. 



In Scotch specimens of Naias flexilis the leaf-sheath is 

 of another type ; the base of the limb widens out into a 

 sheath more than twice the breadth of the limb^ and at an 

 angle of about 45° ; but there is no approach to an auricle 

 on either side. The shoulders of the sheath are crowded 

 with teeth^ but they are infrequent on the sides. See 

 figs. 56 & 57, and compare them with the slightly different 

 figure of Braun on Plate VI. fig. 10. 



Fig. 56. 



l^'ig- 57- 



For drawings of the leaf-sheaths of Naias minor and 

 N. major, see Plate VI. figs. 9 & 29^ and compare the 

 former with Braun^s figure^ Plate VI. fig. 11. 



The margins of the auricles of N. graminea, and more 

 particularly their free extremities and inner sides^ are 

 crowded with strong, spiny, tawny-brown cells, similar to 

 those on the lamina; but they occur at much shorter 

 intervals, and the cells at the base of the spines are more 



