NO. 2260. :sfEW RESTORATION OF TRICERAT0P8—GILM0RE. 



105 



lapping the forward part of the dermosiipraoccipital to which it is 

 closely applied, by squamous suture, thinning out to a thin edge 

 along the line indicated in s. plate 7. From a posterior view Huene 

 depicts the lateral extent of the parietal quite clearly in fig ire 2 of 

 the paper cited above, and Brown also shows its more limited develp- 

 ment in the genus Monoclonlus. (See fig. 2, Bull. Amer. Nat. Hist., 

 vol. 33, 1914, p. 555.) 



All writers are agreed as to the position of the postfrontals as 

 being immediately in front of the dermosupraoccipital (called parie- 

 tal, postfrontals, supratemporals, etc.) bone, but there is much dis- 



S.or. 



"Jif.S/t- 



FiG. 2. — Longitudinal section of brain case of Tkiceratops serratds Marsh No. 

 2416, U.S.N.M. About one-third natural size. a. c. f., anteuiou condyloid 

 foramen ; Al. sp., alisphenoid ; B. oc, basioccipital ; B. oc. pe., basioccipital 

 process; car., foramen for left carotid artery entering pituitary fossa; car. g., 

 groove for eight carotid artery ; ex oc, exoccipital ; f., extent of the articu- 

 lation of the frontal with the underlying orbitosphenoids ; 0c„ occipital 

 condyle; Or. bs., orbitosphenoid ; O. po., paraoccipital process; pit. f., pituitary 

 fossa; Pro., prootic ; S. oc, supraoccipital ; T. m., foramen magnum; v., 

 foramina foh exit of supposed veins ; I, II, III, IV, V, VI, VII, VIII, IX, X, XII, 

 foramina for exit of corresponding cephalic nerves. 



agreement as to the extent of these elements. Marsh, Hatcher, Lull, 

 Brown, and Lambe considered the postfrontal as including nearly 

 all of that portion of the skull between, and including the horn cores 

 and an area on the lateral surface extending down and back of the 

 orbit to its inferior level. Huene correctly recognized a portion of 

 the lateral area posterior to the orbit as being the postorbital and so 

 it stood until the discovery of the Brachycerato'ps skull which dem- 

 onstrates conclusively that the postorbital in that genus includes the 

 horn above the eye and that the lateral extension of the post f rontals 

 is not external but internal to the supraorbital horn cores, as shown 



