494 Frof. T. G. Bonneij— Traverses of the Central Alj)s. 



Hence in order to a2;ree with Loven in the instance of Galeritps, 

 we must have proof that the earliest known species of it had the 

 structures which " were suppressed," Now in "Les Etudes" there are 

 descriptions and delineations of the apical sys-tem of the commou 

 Galerites which, like all Loven's positive work, are marvels of exac- 

 titude. But there is no trace of the fifth plate, nor was the corre- 

 sponding gland evidenced. In fact, there is no evidence whatever 

 that any suppression took place, and it is quite possible that Galerites 

 was the descendant of forms without the fifth plate. 



Loven would have it believed that in long periods of time the 

 fifth basal and gland appeared, the madreporite extended backwards, 

 the ocular plates (radials) grew inwards, and separated the basals. 

 and the position of the anus altered as well as the character of the 

 ambulacra. A new form came from an old one by modification 

 during time. Unfortunately the age of the Cuban forms is not so 

 very long after that of the deposits containing Galerites. Perhaps 

 there was no difference in the times of deposit. For the Cuban 

 deposits are Cretaceous, and not Miocene or later. 



There was no time for the changes. Again, it must be felt, not- 

 withstanding the assertions of the very distinguished naturalists, 

 that there is little or nothing to link the Cuban forms with the group 

 they are presumed to descend from. It must end in confusion worse 

 confounded than the present state of the genera of the Echinoidea, 

 if species are to be associated which have different structures of grave 

 physiological importance. Under the conditions of our present 

 knowledge, it really appears, that although the Cuban forms may 

 have descended from a Galerites, they do not come within the 

 generic diagnosis of the previously known species, and that they 

 are so exceptional as to require entry into another genus. 



III. — Pkeliminaky Note on some Traverses of the Crystalline 



District of the Central Alps.^ 



By Professor T. G. Bonnet, D.Sc, LL.D., F.R.S., Pres. G.S. 



DURING- the past four years I have made several traverses of the 

 Central Alps from north to south, and venture to lay before 

 you the general results as bearing in some respect on the geology 

 of the Highlands. 



1. The ordinary rules of stratigraphy as learnt from most lowland 

 districts are commonly quite inapplicable to the Alps. The most 

 highly crystalline and the older beds often form the higher parts of 

 a mountain region, the newer the lower. The newer beds frequently 

 appear to underlie and dip regularly beneath the older. Gigantic 

 folds, overturns, and overthrust faults abound. The true stratigraphy 

 of a district can only be worked by the exercise of patient and 

 cautious inductions from observations extended over a wide area. 



2. The non-crystalline rocks of the Alps are of various ages. 

 There are some of Carboniferous age, but the great period of con- 



^ Bead before the Geological Section (Section C) of the British Association at 

 Aberdeen, September, 1885. 



