PLATE 17 

 FIG. PAGE 



FRUSTULIA 



1 Frustulia lewisiana (Grev.) De Toni 77 



2 Frustulia rhomboides (Ehr.) De Toni 77 



3 Frustulia rhomboides var. amphipleuroides Grun 77 



4 Frustulia vulgaris (Thwaites) De Toni 77 



5 Frustulia interposita (Lewis) De Toni 78 



6 Frustulia rhomboides var. saxonica (Rab.) De Toni .... 77 



BRFBIS8ONIA 



7 Br6bissonia bu'ckii (Kuetz.) Grun 79 



8 I3r6bissonia palmerii n. sp 80 



AMPHIPLEURA 



9 Amphipleura pellucida Kuetz 78 



10-11 Amphipleura rutilans (Trentepohl) Cl 78 



ANOMCEONEIS 



12 Anormi'oneis serians (Breb.) Cl 80 



13 Anomoeoneis serians forma minor 80 



14 Anomoconeis follis (Ehr.) Cl 80 



TRACHYNEIS 



15 Trachyneis aspera var. intermedia Grun 79 



MASTOGLOIA 



16 Mastogloiu kinsmanii Lewis 87 



17 Mastogloia angulata Lewis 87 



18 Mastogloia lanceolata Thwaites 87 



19 Mastogloia smithii Thwaites 87 



20 Mastogloia elegans Lewis 87 



21-22-23 Mastogloia apiculata Wm. Sm 87 



24 Mastogloia exigua Lewis 87 



