10 EXPLANATION OF THE PLATES. 



PLATE XXVII. 



Zygnema rivulare. 



PLATE XXVIII. 



Figs. 1 and 2. Zygnema quininum. Figs. 3 and 4. Zyg- 

 nema cestivum. Figs. 5 and 6. Zygnema commune. 



PLATE XXIX. 



* Zygnema varians. 



PLATE XXX. 



Figs, land 2. Zygnema malformatum. Figs. 3 and 4. Zyg- 

 nema catena>forme. Figs. 5 and 6. Zygnema gracile. 

 Figs. 7 and 8. Zygnema parvum. Figs. 9 and 10. Zyg- 

 nemaflavescens. 



PLATE XXXI. 



Figs. 1 and 2. Zygnema Grevilleanum. Figs. 3 and 4. Zyg- 

 nema longatum. 



PLATE XXXII. 



Figs. 1 and 2. Zygnema inequale. Figs. 3 and 4. Zygnema 

 subventricosum. Fig. 5. -Zygnema subventricosum var. 

 Figs. 6 and 7. Zygnema inflatum. Fig. 8. Zygnema in- 

 flatum var. Figs. 9 and 10. Zygnema tenuissimum. 



PLATE XXXIII. 



Fig. 1. Zygnema rostratum. Fig. 2. Zygnema Woodsii. 

 Fig. 3. Zygnema r ever sum. 



PLATE XXXIV. 



Figs. 1, 2, 3. Zygnema angulare. Fig. 4. Zygnema abbre- 

 viatum. Fig. 5. Zygnema malleola. Fig. 6. Zygnema 

 affine. 



PLATE XXXV. 

 Zygnema mirabile. 



