430 Dr. G. T. Trechmann— 



of any debris of the Blue Mountain series in it, and consequently 

 there is no reason to suppose that any portion of the present 

 Jamaica protruded as a land surface during its formation. 



Observations on Sawkins's Map. 



Some caution is necessary in reading Sawkins's map. The original 

 manuscript map, on a large scale, is still preserved in sections in the 

 Jamaica Institute at Kingston, but the colours are largely faded, 

 and the map is much eaten by white ants. The map in the survey 

 memoir, however, seems to be a faithful reproduction of it. 



The grey colour of the Carbonaceous Shale (Richmond beds) is 

 almost exactly similar to that of the White Marls lyiug above the 

 White Limestone. 



Some areas of Cretaceous Limestone mentioned in the text are 

 not indicated on the map, notably one in the far west of the island 

 between Grange and Bosleys. Some limestones mapped as 

 Cretaceous belong to the Carbonaceous Shale series. The Barrettia 

 Limestone at Haughton Hall, near Green Island, in the north-west, 

 is not indicated, but then it appears to have been unknown to the 

 surveyors in 1862. 



In the centre of the island, in the Rio Minho watershed, the beds 

 below the Cretaceous Limestone are indicated as " metamorphosed 

 series ". They are not in reality metamorphosed, as some parts of 

 the same formation in the Blue Mountains are. Dr. D. Woolacott 

 traversed this area two years ago and agrees with me on this point. 

 In the far south-west and west there are considerable areas coloured 

 green to indicate the Yellow Limestone. The beds, apparently 

 Hill's Manchioneal formation, are certainly limestones of a very 

 yellow colour, and owing to the confusion of the position of the 

 Bowden beds they are correlated by Sawkins with the true Yellow 

 Limestone of the centre and east of the island, whereas most of them 

 seem to belong to the series lying above the White Limestone 

 associated with the Bowden beds. There are other instances one 

 might mention, but the map, everyone will agree, is a marvel of 

 industry and elucidation when one has regard to the physical 

 difficulty and discomfort and the period at which it was made. 



Pal^ontological Notes. 



The fossils collected along the section between Cambridge and 

 Catadupa, illustrated by Fig. 3, are not yet worked out, and so 

 I cannot at present indicate more than a few of the genera that are 

 present among some hundreds of species gathered from this and 

 numerous other localities in Jamaica. 



The Calcareous shales below the Rudist Limestones in the section 

 illustrated contain Trigonia, Roudairia, Janira, Plioladomya, and 

 echinoderms, and corals of Cretaceous aspect. 



These shales agree with part of the beds mapped by Sawkins as 

 Trappean, and a similar looking and apparently similarly situated 



