308 M. T. C. Winkler on 
in them an analogy. Probably the ambulatory legs of Pem- 
phiz were monodactyle, like those of the Glyphee. 
Let us now examine the analogies :— 
In Pemphix Sueurt we find the cylindroid form of the 
cephalothorax of the Glyphee. Like that of the Glyphee, it 
is covered with tubercles and divided by impressed lines or 
grooves. Von Meyer described the carapace of Pemphix as 
granulated and covered with tubercles. 
The outer antenne of Pemphix are long, multiarticulate, 
and situated upon jointed peduncles, exactly like the outer 
antenne: of the Glyphee. On the first joint of the antennary 
peduncle we observe a protective scale or movable lamina, 
resembling the scale which protects the peduncle of the outer 
antenne of the Glyphee. : 
The inner antenne of Pemphix are shorter than the outer, 
and terminate in two filaments, like the same organs in the 
Glyphee. 
The caudal fin of Pemphix exactly resembles that of the 
Glyphee; we again meet with the same characteristic form of 
the seventh segment of the abdomen and the same form of 
the lateral plates of the sixth segment, of which the two outer 
are divided into two parts by a transverse line as by a 
hinge. 
The abdomen in Pemphix is exactly analogous to that of 
the Glyphee; and the same may be said as to the general 
habit of Pemphia Sueurt. 
Considering the very great resemblance of the organization 
of Pemphix to that of the Glyphee, and at the same time the 
comparatively unimportant differences which distinguish the 
latter from the former, is it not permissible to see in the genus 
Pemphix the Triassic ancestor of the genus Glyphea? No 
doubt in the geological ages which separate the formation of 
the beds of the Triassic epoch from the times in which lived 
the species of Crustacea whose petrified remains we find at 
present in the sediments and deposits of the Jurassic, Creta- 
ceous, and Tertiary epochs, some anatomical characters may 
have been changed or modified: the arrangement of the 
grooves of the cephalothorax may have become different from 
what it was; the cephalothorax may have become more 
adorned with tubercles; the rostrum may have become less 
produced ; and in this way the descendants of the genus 
Pemphizx presented themselves under the form of the genus 
eerie in the period that immediately succeeded the Triassic 
epoch. 
