CRASPEDODISCUS. 



515 



GENUS 179.- CRASPEDODISCUS EHR, 1844. 



Fig. 268. Craspedodiscus insignis. 



Valve usually circular, with cellular structure, having a broad 

 border of structure different from that of the centre, from which it is 

 separated by a well-defined margin, without spines. 



I give in the text, after Dr. Ad. Schmidt, a figure of Cr. insig?iis, A. Schm. 

 This form has been found at Nankoori, in the Nicobar Islands. 



Authors have described about 20 species belonging to this genus. Those 

 most frequently met with in collections are C. Coschiodiscas EJir., and C. 

 elegans E/ir., both fossil, and found in the fossil deposit of Nottingham, 

 Maryland. 



In the forms which I have been able to examine, it is a depression of the 

 valve which produces the singular appearance which is characteristic of the 

 genus. 



