412 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 
extends slightly medial to it. The similar relations of this and the 
medial element in the lizard are at once evident and show that it must 
be regarded as the supratemporal. 
In this connection it is worthy of note that Parker (’78, p. 406) says 
that in ripe embryos of Tropidonotus “inside the middle of the squam¬ 
osal there is a small suboval scale of bone, the supratemporal, here it 
is only distinct for a time, but in the lizard permanently so.” Parker 
gives no reference to figures and so it is difficult to say exactly what he 
means, especially since he (’79) has become confused in the termin¬ 
ology of the temporal elements in the lizard. He (’78, pi. 31, fig. 7), 
however, gives a figure in which an oval scale is shown ventral to the 
1 squamosal’ (my supratemporal), and this, it may be, is the true 
Fig. Q. — Side view of the skull of Crocodilus palustris (embryo 10 inches long), 
after Parker. J., jugal; Pa., parietal; Po., postorbital; Qj., quadrato- 
jugal; Qu., quadrate; Sq., squamosal. 
squamosal, since, by comparison with the lizard, it lies in the proper 
position for that bone. If this be true then there can be no doubt that 
the bone which persists in the adult is the supratemporal. It should 
not be forgotten that Gaupp (’94, p. 87, footnote) was not able to find 
this bone in the one stage of Tropidonotus at his command. 
Crocodilia .— In the temporal region of the Crocodilia there are, 
as a rule, two arcades and two temporal vacuities. The upper arcade 
(fig. Q) is formed by the postorbital (Po.) and a bone (Sq.) occupying 
the postero-lateral superior angle of the skull. Cuvier called this the 
