10 EXPLANATION OF THE PLATES. 



PLATE XXVII. 



Zygnema rivulare. 



PLATE XXVIII. 



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

 nema (estivum. — Figs. 5 and 6. Zygnema commune. 



PLATE XXIX. 



Zygnema varians. 



PLATE XXX. 



Figs, land 2. Zygnema malf or malum. — Figs. 3 and 4. Zyg- 

 nema catenceforme. — Figs. 5 and 6. Zygnema gracile. — 

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

 nema flavescens. 



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- 

 fiatum var. — Figs. 9 and 10. Zygnema tenuissimum. 



PLATE XXXIII. 



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

 Fig. 3. Zygnema reversum. 



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. 



