CONTENTS. 



Paoe 



Echinodiscus tenuissimus 



(Agass. & Des.), Plate 



125, figs. 11, 12 . . 



Echinodiscus bisperforatus 



Leske 



Echinodiscus bisperforatus 



var truncatus Agass. . 



Astridypeus \'errill . . . 



Astriclypeus maniii Verr. 



Plate 12.5, figs. 13-15 . 



Encope Agassiz .... 



Key to the Species of Encope . . 



Encope emarginata (Leske) 



Plate 12.5, fig. 25 . . 

 Encope micropora Agass. 

 Encope perspectiva Agass. 

 Encope niichelini Agass 

 Encope californica Verr. 



72 

 72 



7.3 



74 

 74 

 74 

 75 

 75 



Encope grandis Agass., 

 Plate 125, fig. 24 . 

 Mellita Agassiz . . . 

 Key to the Species of Mellita 



Mellita quinquiesperforata 

 (Leske), Plate 125, figs 



16-21 



Mellita longifissa Mich. 

 Mellita sexiesperforata 

 (Leske), Plate 125, figs 

 22, 23 .... 

 Mellita pacifica Verr. 

 Rotula Agassiz .... 

 Key to the Species of Rotula . 

 Rotula orbiculus (L.) . 

 Rotula deciesdigitata 



(Leske) 



Explanation of Plates 



Paof. 



75 

 76 



7(i 



76 



77 

 77 

 78 

 78 

 78 



