PLATE LI 1 1. 



Pig. l. — .v.r ;,•//',; undata Mann. Enlarged 990.diameters. Description, p. 866. 

 Fio. j — At "■"'•! ardua Mann i vulval view |. Enlarged 600 diameter* Deecriptloti, p. 336. 

 Mann zonal view). Enlarged 600 diameters. Description, p. SM, 

 ; —Naricula prodiga Mann. Enlarged 600 diameters, Description, p. B 

 Pig 5.— Navicuta pinguis Mann. Enlarged 375 diameters. Description, p. 860. 

 Fig. 6. — Navicula i\ ■ itsta Mann (type), Enlarged 376 diameters. Description,] 

 enusta Mann (form). Enlarged 875 diameters. Description,] 







