EXPLANATION OF THE PLATES. 11 



PLATE XXXVI. 



Zygnema Hassallii. 



PLATE XXXVII. 



Figs. 1 and 2. Zygnema quadratum. Fig. 3. Zygnema in- 

 termedium. Fig. 4. Zygnema diductum. Fig. 5. Zyg- 

 nema vesicatum. Fig. 6 and 9. Zygnema Jenneri. Fig. 7. 

 Zygnema dubium. Fig. 8. Zygnema minimum. 



PLATE XXXVIII, 



Fig. 1. Tyndaridea cruciata. Figs. 2 and 3. Tyndaridea 

 anomala. Fig. 4. Tyndaridea lutescens. Fig. 5. Tyn- 

 daridea bicornis. Figs. 6 and 7. Tyndaridea insignis. 

 Fig. 8. Tyndaridea ovalis. Fig. 10. Tyndaridea stag- 

 nalis. Fig. 9. Tyndaridea stagnalis var. ? 



PLATE XXXIX. 



Figs. 1 and 2. Tyndaridea conspicua. Fig. 3. Tyndaridea 

 immersa. Figs. 4 and 5. Tyndaridea Ralfsii. Fig. 6. 

 Tyndaridea decussata. 



PLATE XL. 



Fig. 1. Mougeotia major. Fig. 2. Mougeotia geniiflexa. 



PLATE XLI. 



Fig. 1. Zygogonium ericetorum in its terrestrial condition. 

 Fig. 2. Aquatic form of the same. 



PLATE XLIL 



Fig. 1. Mesocarpus scalaris. Fig. 2. Mesocarpus scalarisvar. 



PLATE XLIII. 



Fig. 1. Mesocarpus intricatus. Fig. 2. Mesocarpus recurvus. 



PLATE XLIV. 



Fig. 1. Mesocarpus depressus. Fig. 2. Mesocarpus ovalis. 



