26 



Bulletin 30 



443 



Zone I. Above Caimito. Orchid gorge. Hard greenish clays 



with Tellinas. River narrows. Approximate thickness 50 



Two miles above Caimito. Sandy clays with fossils in lenses. 



Irregular concretions. BullaiHa Sarahberlineree found here. 



Thickness about 50 



Sandy clays with lignitic streaks resembling those at Sabaneta. 



Approximately 100 



Unexplored. 



Presence of Gypsum. — From the Chione layer to the top of 

 the Fucoid and Bryozoan beds gypsum is found both as thin 

 plates filling nearly vertical cracks, and as clear, transparent" sel- 

 enite crystals. The shells of Scapharca patricia are also all en- 

 crusted with gypsum crystals. 



The presence of gypsum indicates a period of aridity and 

 excessive evaporation. It recalls the gypsiferous strata of the 

 Grand Gulf beds. 



Fauna of Zone H. — We found a rich fauna with many bor- 

 ing molluscs in the corals. 



List of Species 



Acteocina canaliculata Say. Area occidentals Philippi. 



Acteoeina (Cylichnella) Area umbo nata Lamarck. 



triticum-tritonis, 11. sp. Barbatia submarylandica, n. sp. 



Retusa yaquensis, n. sp. Scapharca golfoyaquensis, n. sp. 



Bullaria paupercula Sby. Scapharca caimitica, n. sp. 



Terebra Berlinerce, n sp. Scapharca riocanensis, n. sp. 



Conus haytensis Sby Scapharca Willardausteni, 11. sp. 



Conus proteus Hwass. Pecten nodosus Linne. 



Conus furvoides Gabb. Botula hispaniolse, 11. sp. 



Conus Kitteredgei, n. sp. y Lithophaga antillarum d'Orb. 



Conus recognitus Gpy. / Lithophaga nigra d'Orb. 



Cythara elongata Gabb. Mytilopsis domingensis Recluz. 



Cancellaria Harrisi n. sp. Coralliophaga corulliophaga Gm. 



Oliva cylindiica Sby. Chama caimitica, n. sp. 



Oliva Cristobalcoloni, n. sp. Chama congregatoides, n. sp. 



Oliva brevispira Gabb. Chama riocanica, n. sp. 



Olivella muticoides Gabb Codakia orbicularis Linne. 



Mitra Henekeni Sby. Lucina chrysostoma Philippi. 



Fusus Henekeni Sby. Miltha riocanensis, n sp. 



Fusus Henekeni Veatchi, n. var. Phacoides yaquensis Gabb. 



