PLATE Vni. 



I'IG. 



1, 2, 3, & 4. — Varieties of Haliomma. Ilaliomma Ilumboldtii (?) of 

 Ehrenberg, from Cambridge, Barbados, numerous and variable. 

 Altlioiigli there are sometimes indications of spines radiating 

 from the centre, as in Stylodictya, yet the points romid tlie ed<^e 

 apjiear to be merely "marginal aiipendages." — Diameters, in- 

 cluding spines, from .0077 to .0085. 



5, & 0, — Miiller describes these as stages of growth oi the Haliomma, 

 where the outer web is spiiming itself over and ror.nd the central 

 nucleus, and the siliceous rafters or supports extending like a 

 framework from the micleus to the exterior covering. (Page 21 

 of "Thalassicollen Polycystineu, «&c., des Mittelmeeres.") 



7 & 8. — Spines or Spicules in Barbados deposit. 



