Smithsonian Report, 1936. — Conger 



Plate 13 



***'w^i4M' 



Various shapes of diatoms, and types of structure. 

 Upper left, SI ictodiscus radfordianus Cast. X 320. Center right, Hyalodiscus crepitans Mann. X 170. 



Upper right. Stictodiscus eulensteinii (Qrev.) Cast. Lower left, Coscinodiscus marginatus Ehr. X 300. 



X 320. Lower right, Asterolampra vulgaris Grev. X 540. 



Center left, Brighlirellia pu/chra Gruii. X 500. 



