1002 The American Naturalist. [ November, 
ing the Amphisbenians and Anniellide to be exceptions; but the 
Geckonidz and Uroplatidæ also lack the prosquamosal. Therefore, 
this character does not hold. 
A third distinction according to Prof. Cope is that the quadrate bone 
is supported by the paroccipital [squamosum] in the snakes, and the 
exoccipital [paroccipital] in the Lizards. In the Mosasauridz the 
squamosal (paroccipital) is said to be more largely developed than in 
the Lacertilia, and that it supports the quadrate bone as in the 
Ophidia. 
This is by no means correct. It is the squamosal (paroccipital, Cope) 
which supports the quadrate in most of the Lacertilia; in some forms 
only, the paroccipital (exoccipital, Cope) takes part (Chameleon). 
But in many Lizards, the Iguanide for instance, the paroccipital pro- 
cesses do not support the quadrate at all. This character, therefore , 
falls to the ground. I can not see any principal difference in the rela- 
tion of the squamosal (paroccipital, Cope), the paroccipital (exoccipital, 
Cope) and quadrate in the Mosasaurs and the Iguanide. In the 
squamosal (paroccipital, Cope) of Platecarpus (fig. 20, 21, Pl. IL) of my 
paper we can distinguish 3 portions: first, an upper one, which joins the 
parietal processes; second, an inner one which is suturally united with 
the paroccipital and petrosal, and a lower one, which supports the 
quadrate. 
In a skull of Conolophus (Iguanide) before me, I find very similar 
conditions, the inner process only is not so much developed, but it 
reaches the petrosal. The differences enumerated by Prof. Cope be- 
tween the Lacertilia and Mosasauride do not exist; and I can not dis- 
cover one trace of a character of the snakes. The phlogenetic conclu- 
sions of Prof. Cope are not supported by the facts. I believe as firmly 
as formerly, that the Mosasauridz are true Lacertilia adapted to aquatic 
life; and that their closest living representatives are the Varanide. 
The Varanidæ haveretained the terrestrial limbs, and the free nasal bones 
but have lost the postorbital bar. The Mosasauride have required fins 
with digits? with numerous phalanges, the nasals have become united 
with the premaxillaries, but the postorbital arch has been retained. 
®In a specimens of Thorosaurus, which I have lately examined through the 
kindness of my friend, Prof. S. W. Williston, Lawrence Kas. I find in the fore- 
limb the following number of phalanges. 
Ist. digit 5 (+3); probably 8, the 5 proximal ones are preserved. 
2nd. digit 7 (+2); probably 9, the 7 proximal ones are preserved. 
3rd. digit 9 (+1); probably 10, the 9 proximal ones are preserved. 
5th. digit 10 (+1); probably 11, the 10 proximal ones are preserved. 
Sth. digit 11 or 12; all preserved, but some covered up. 
