COSCINODISCUS. 



535 



The following genera are very approximate to the Coscinodiscus and 

 should probably be combined with this genus : 



1 





X. 



. . r - . . <t>C On~ 



--V 



** 



*& 



' I*:*:'--. : ^^ 



< *^*W.J,^w--~'~ 



.-*" 



Fig. 280. Ethmodiscus punctiger. 



EthmodisCUS Ca.Str. , 1886 This genus includes the Coscinodiscus 

 with very fine puncta. Figure 280 in the text shows a form of this genus 

 Ethmodiscus punctiger Castr., which has been found in Yeddo Bay. 



Haynaldiella Pant., 1892 (Haynaldia Pant. olim). 



Valve circular, convex, with small plane central area, margin 

 striate, very distinct. Structure striolate, llame-like, with striae 



forming radiating lines. 



