PROM THE UPPER GREENSAND. 21 



The species has great resemblance to the lower part of Onchotrochus serpentinus, 

 nobis. Very careful examination of sections and calices proves that there is no columella, 

 that the inner ends of the septa produce a false one, and that the styloid appearance is 

 due to fossilization. 



The discovery of better specimens may, perhaps, lead M. de Fromentel to consider his 

 Stylotrochus, which resembles this form, to be of the same genus. 



Pamilt— ASTR^IDiE. 



Division — Stylinace^. 



Genus — Ctathophora, Michelin. 



This genus has the usual characters of compound Astrtsince, but the dissepiments act 

 as tabulae, and shut in the calice below, just as in some of the Liassic Isastrcem. There 

 is no columella. The curved dissepiments are not noticed, and the family of the genus 

 must remain unsettled, for the minute structure is clearly tabulate. The genus flourished 

 in the Lower and Middle Oolites, and the only Cretaceous species is that under considera- 

 tion, and which has been described by D'Orbigny from the Craie tuffeau of Martigues. 



1. Cyathophora montictjlaria, jyOrh., sp. PL VIII, figs. 15 — 18. 



The septa are rather thick. 



There are three cycles, but the third is often deficient in one or two systems. 



Locality. Haldon. In the Collection of the Geological Society. 



Division — Favia ce^ . 



Genus — Favia, Ehrenberg. 



This genus has absorbed the Parastrceacece, so that the old Daraslrma stricia, EJ. and 

 H., is now named Favia stricta, Ed. and H. 



