THE SKULL OF PALEORHINUS Bx) 
of the pterygoids in the roof of the palate, which von Meyer did not 
do. Cope (Syl. Lect. Vert., p. 72) figures the transverse, but his 
figures do not show any sutures. 
E. Koken discusses Belodon briefly in his paper on Thoraco- 
saurus macrorhynchus in Zeitschr. d. Deutsch. geol. Gesellschajt, 
Jahrg. 1885, pp. 763-65. He recognizes the separate existence of 
the transverse in the following statement, which he makes under 
heading 4: 
Zusammen mit den Palatinen und Transversen umschliessen sie [Pterygoids] 
schmale Gaumenlécher, von deren Umgrenzung der Oberkiefer ausgeschlossen 
ist und die denen der Crocodiliden gar nicht gleichen, sondern ganz auf Lacertilier 
herauskommen. Auch das starke Vorspringen der Ossa transversa ist Eidechsen- 
character. 
The transverse is recognized as a separate bone by McGregor 
in his. paper already quoted, where he describes and figures the 
bone. His illustrations give an excellent idea of the form of the 
transverse and of its sutural relations. McGregor, however, omitted 
mention of Koken’s article cited above, and does not include it in 
his bibliography. But since the latter’s paper appeared many years 
previous to that of McGregor his description of course has priority 
as being, so far as is known to the writer, the first recognition of the 
element under discussion. 
Pterygoid.—The pterygoid may be said to consist of three parts: 
first, the broad, thin, flat bone which forms a considerable part of the 
palate from the internal naris back almost to the rear end of the 
transverse; second, the short, almost vertical lateral extension already 
mentioned as united to the transverse; and third, a long posterior 
wing which unites with the quadrate. The entire length of the bone 
is seven and one-half inches and the greatest width, that across the 
lateral wing, must be about three and one-fourth inches. The ante- 
rior extremity forms the outer half of the posterior border of the 
internal naris and extends for perhaps one-half inch along the outer 
margin. The bone widens gradually backward for three inches 
and then gives off the lateral extension. The anterior portion is 
terminated behind very abruptly by a sharp-edged, vertical, trans- 
verse process which marks the beginning of the posterior wing. At 
first the lateral wing is only five-eighths inch wide, but it broadens 
