1889.] Geology and PalcEontology . 627 
Society of France. An ophitic band extends in a W. N. W. to E. S. 
E. direction from the coast of the Province of Cadiz to the Sierra de 
Moron ; here it bends to the east until it reaches Antiquera, where 
it again bends northwards, until it dies out in the Province of Jaen. 
The direction of the band is influenced by that of the cordillera, and 
its width in general diminishes as it recedes from the coast. Whoever 
traverses this region is struck by the difference between its orography 
and vegetation and those of the rest of Andalucia. This ophitic band 
is not confined to one geological stratum, but traverses Liassic, Neo- 
comian, and lower Tertiary beds, so that the metamorphism has been 
effected by a similar series of causes acting upon different materials, 
and therefore producing different results. Throughout the band 
innumerable points of crystalline rocks exist, and have been desig- 
nated ophites by Mr. Macpherson, who compares them with similar 
rocks in the Pyrenees. These ophites occur in masses of no great 
size and of circular form, and often in rounded hills, covered from 
the base to summit with many-sided fragments of the same rock. 
More than four hundred of these ophitic points are known at various 
levels, and many others must be hidden. Two theories have already 
been put forth with regard to the origin of ophitic rocks : that of a 
magma coming from the interior of the globe, and that of chemical 
deposition, without heat, in the depths of seas, where the debris of 
primordial rocks have accumulated. This latter theory is sustained by 
MM. Verlet d'Aoust and Dieulafait. 
M. Calderon adds a third theory, which he believes to be the only 
one that will explain the phenomena to be found in Andalucia and in 
the Pyrenees. He maintains that oi)hites are the products of a vast 
metamorphism produced by orogenic movements upon argillaceous 
rocks impregnated with divers chemical elements. The relations which 
always exist between these ophites and the movements which have 
taken place in the formations in which they lie have long been known 
to geologists, but, taking the effect for the cause, they have believed 
that the ejaculation of igneous matter from the interior of the earth 
has been the cause of the movement of the strata, and also of the 
chemical transformations. For the region treated of no trace of those 
phenomena of contact which show the influence of matter in fusion, 
and no trace of vents of eruption, have been found. The ophitic 
rock has not penetrated the beds, and usually lies at the bottom of the 
folds. The clayey and marly beds, permeated with other minerals 
and with water, have brought together into the cul-de-sac formed by 
their folds all the conditions necessary for a chemical change, and 
