166 §=©Reviews—Prof. A. Gaudry’s Permian Reptilia, ete. 
preoccupied name Platyceps has been recently applied to an allied 
form from approximately equivalent beds in New South Wales. 
In the New World the strata in North America commonly termed 
Permian have also yielded a number of kindred forms, such as 
Trimerorhachis, Eryops, Zatrachys, Cricotus, etc. Whether these 
numerous forms should be referred to one or more families, or 
whether several of the genera will subsequently have to be united, 
is a matter of but little moment; their interest lying in the evidence 
they afford that at an early epoch of the world’s history the 
terrestrial vertebrate life over at least a large part of the surface of 
the globe presented the same general facies. 'To assume, however, 
that these different forms existed at precisely the same absolute date 
in widely distant regions is clearly illogical. But if we have only 
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HF. 
Fic. 2. Left lateral and posterior views of a vertebra of Euchirosaurus Rochei, nat. 
size. m. neural spine, with lateral expansions a/.; s. suture between spine and 
arch ; za. zp. anterior and posterior zygapophyses; d. transverse process; ¢. 
costal articulation; p/.c. pleurocentrum; ?.c. intercentrum; ¢.7. neural canal ; 
not. notochordal vacuity. 
to reckon by the evidence of land deposits, and are careful to use 
the term homotaxial equivalency in its proper original sense (?.e. as 
essentially implying the absence of absolute synchronism), then it 
may be convenient to provisionally regard the deposits in which 
most of these Labyrinthodonts occur as of Permian, or perhaps in 
some cases of Lower Triassic, age. It may, however, happen that, 
to use Professor Huxley’s graphic simile, we shall eventually be 
able to correct our terrestrial clock by our marine clock, when we 
may find that the former has lagged behind, so that our European 
