GEOLOGICAL VIEW. 59 



belongs to this formation ; it also contributes to form the best 

 soil of Oropuche. The series extends from west to east very 

 nearly to the Ortoire, on a breadth of from two to four 

 miles. 



3rd. Tamana or Calcareous Series. The limestones of this 

 series — viz., of Montserrat, Tamana, and Lebranche — vary from 

 granular to crystalline in texture, and form, with sandstone, cal- 

 careous sandstones pretty common. The stratum can be traced 

 from Cedar Hill Estate, Savanetta, to Manzanilla, eastern 

 shore. Messrs. Wall and Sawkins are of opinion that the thick- 

 ness of these strata cannot be less than several hundred feet. 



4th. The Nariva Series consists of ferruginous clays, form- 

 ing the substratum of the well-known red soil, stiff and retentive, 

 and particularly observable in the county of Victoria. 



5th. The Moruga or Arenaceous Series may be followed up 

 from the southern coast to the Ortoire and the Oropuche lagoon, 

 and from Mayaro, eastern coast, to Guapo and Cedros, western 

 coast. The strata in this series are more or less of light sand ; 

 calcareous sandstones, however, are not deficient. This admix- 

 ture of the calcareous element accounts for the quality of the 

 soil where it exists in certain proportion, as at Guayaguayare, 

 Moruga, Erin, and Cedros, where cacao and the sugar-cane are 

 cultivated to advantage. Asphaltum is extensively disseminated 

 in this series ; lignite is found on the southern coast. We 

 should also look for mud volcanoes or salses in this series. 



I may be permitted to add a few particulars. Transition 

 limestone prevails not only at La Ventille and the islets in the 

 gulf, but is also met with in the mountains which border our 

 valleys, between Diego-Martin and Cuesa ; in the valley of 

 Maraval, particularly on the Moka Estate ; between Santa Cruz 

 and Maracas Valley; between the sources of Arima and Oro- 

 puche, and more eastward still. At the head of the rivers Aripo 

 and Oropuche there are some caves beautifully ornamented with 

 stalactites and stalagmites; they are haunted by Guacharos, 

 which breed therein. Our limestone is, in general, compact, of 

 a bluish-gray colour, destitute of organic remains, and traversed 

 by veins of calcareous spar. Small crevices occur in the calca- 

 reous rocks, lined with a beautiful crystallisation of carbonate of 

 lime of a topaz colour. 



Gypsum is not uncommon, and there is a quarry of it near 



