266 FORAMINIFERAL ROCKS ON WEST COAST OF SANTO, 



The organic fragments comprise Lithothamnion (branching 

 form), foraminifera, echinoid spines and molluscan shell-fragments. 

 The Foraminifera are as follows : — 



1 Truncatulina. 



Carpenteria sp. 



Lepidocycliyia afF. insulce-natalis, Jones it Chapm. 



199. — " Lower portion of sedimentary' beds, C. Karai, Santo." 

 A volcanic tuff with a few organic particles. The rock is 



largely composed of pyroxenic and other minerals. 



One test of a foraminifer, apparently referable to Glohigerina 



conglobata, Brady, was noticed. 



208.— "Older sedimentary beds (dipping 55°) of the Wai 

 Bubo, Santo." 



A fine-grained calcareous and tufaceous mud, with occasional 

 tests of a starved Glohigerina (aff. hulloides, d'Orb.). 



210. — "Older sedimentaries of the Wai Bubo at the farthest 

 point reached^ Santo." 



A brecciated limestone, chiefly organic, but intermixed with 

 crystals and fragments of igneous rocks. 



The following organisms, badly preserved, were recognised : — 



Lithothamnion (branching form). 



Heterostegina sp. (fragmentary); numerous. 



? Lepidocyclina. 



21 Ic. — "Limestone pebbles, in tuif dipping 55°, Wai Bubo, 

 Santo." 



A compact grey or greenish limestone. The microscopic 

 structure is seen to be largely that of a foraminiferal limestone; 

 the organic material is admixed with some andesitic fragments, 

 and minerals such as felspar, and altered ferro-magnesian silicates. 

 The cement of the rock is in parts a tufaceous mud, in other 

 places a crystalline cement. Besides foraminifera (of which 

 there is in this rock a great variety) there are numerous examples 

 of Lithothamnion^ both branching and encrusting, echinoid spines 

 and plates, and molluscan shell-fragments. The structure of the 



