“a 
i! 
Reviews—De Lapparent—Inequalities of the Globe. 821 
Paleoniscid one. The Platysomidw are specialised Palaoniscide.” 
And from these facts, founded upon minute study and comparison, he 
thinks he is justified in concluding :— 
“1. That the Platysomide are specialised forms, which have, if the 
doctrine of descent be true, been derived from the Palzoniscide. 
Their structure presents us simply with a modification of the 
Palzoniscid type, and wherever the Paleeoniscidz are placed in the 
system, thither the Platysomide must follow. 
“2. The resemblances between the Platysomidee and the Dapediides 
and Pyenodontide are mere resemblances of analogy, and not of real 
affinity. The Dapediide are related not to the Palzoniscide or 
Platysomide, but to the other semiheterocercal Ganoids of the Jurassic 
era (Lepidotus, etc.), and the Pyenodonts are highly specialised 
forms, whose general affinities point in the same direction.” 
This memoir is a valuable instalment to the series of papers 
previously published by the author relating to the history and 
classification of the fishes of the Coal-measure and other Paleozoic 
deposits ; a subject upon which he has long been occupied. It is 
illustrated with four excellent plates, containing upwards of 60 
figures, drawn chiefly by himself, which is a guarantee for their 
accuracy. 
I.—L’Orteine pes InfGarites De LA SurFace pu GuLose. By 
A. pe Lapparent. Revue des Questions scientifiques, July, 1879. 
S people get old, their clothes sometimes become too large for 
them; and so it seems to be with the earth, whose surface 
behaves like a cloth forced into wrinkles by the diminution in 
volume of its support due to secular cooling. 
In the application of this principle les the clue both to the 
existing orography of the globe, and also to many of the phenomena 
of geology, as is ably argued within the compass of twenty-four 
tersely written pages. 
The terrestrial surface bears throughout the mark of a lateral 
thrust, which has found in the mountains its supreme expression. 
These represent the salient portion of the wrinkles, and thus the 
idea of upheaval has a certain justification—none the less, because 
these local upheavals are the result of a general sinking of the crust. 
The author is desirous to disconnect Elie de Beaumont with Von 
Buch’s “crater of elevation” theory. Far otherwise is the real 
structure of mountain chains, which are often composed of stratified 
rocks, either with or without a crystalline nucleus, than of volcanic 
cones, and it usually happens that the crest does not occupy a 
central position with two symmetrical slopes, but the chain is 
unsymmetrical, having its steepest side towards the sea. This rule 
may not be true of all chains as they at present exist, but we must 
remember that they are of different gevlogic ages, and that each was 
accentuated at a certain epoch, which should be deemed its age. The 
normal, however, is an oceanic depression sloping gently towards 
its line of greatest depth, from which at a high angle spring the 
submerged and emerged portions of the coast chain, to slope away 
DECADE I1.— VOL. VII.—NO. VII. 21 
