WCHICF.RATOI'S I.ONGIROSTRIS 105 



"The lui.uil /torn core ... is triangular in cross-section with the apex of the triangle above, and 

 ir points forward and upward. Vascular grooves are not so well developed as on the brow horns, 

 but there is no doubt it carried a fair-sized horny sheath. 



". . . The orbit is moderately large and circular in outline. . . . 



"The broic horn cores ... are moderately large and circular in cross-section, except at the base 

 where they are sub-triangular. They rise from the supero-posterior border of the orbits and con- 

 tinue upward, forward, and slightly outward, thus differing from A. ornatus in which they curve 

 outward, then forward. They taper gradually to the tip, but are farther apart at the base and much 

 smaller than those of A. ornatus. The horn cores bear well-defined, longitudinal, vascular 

 grooves. . . . 



"The [post] frontal jontanelle is closed superiorly, due to the union of the [post] frontals, 

 thus completing the secondary roof on the superior surface. This [post] frontal fontanelle opens 

 posteriorly, however, and, apparently, is larger than in A. ornatus. . . . 



"The supratemporal fossae do not appear to differ materially from those of A. ornatus. They 

 open posteriorly, as in that species and in the genera Torosaurus and Triceratops. 



"The crest is large, rectangular, and quite flat. . . . The fontanelles are proportionately much 

 longer than in A. ornatus and, as in that species, are wholly within the parietals. The crest is rela- 

 tively thin, especially in advance of the fontanelles. The maximum thickness of the crest, through 

 the posterior portions ... is 30 mm., but the average thickness is not more than half this. 



"The squamosals are long and narrow. . . . The epoccipitals are so thoroughly fused with the 

 squamosals that they appear as serrated edges rather than separate ossifications. The same is true 

 of the large epoccipitals on the posterior edge of the parietals. The squamosals are marked by 

 vascular grooves both above and below. 



"The parietals resemble those of A. ornatus., but are thinner, and the epoccipitals are much 

 thinner and smaller. As in A. ornatus, there is a pair of short, thick, hook-like processes, thoroughly 

 fused to the median posterior extremity of the superior surface of the parietals. On the superior 

 surface of the parietal, in advance of the fontanelle, there is an area in which the surface is lower 

 than the rest of the bone and quite smooth. This is a backward extension of the floor of the supra- 

 temporal fossa and the bone is very thin. Except for these areas in advance of the fontanelles the 

 parietals are covered with vascular markings." 



Dimensions of Type 



(From Sternberg) 



Length, tip of rostral to extremity of crest 1660 mm. 



Greatest breadth of skull (anterior portion of crest), as restored 730 



Breadth of posterior portion of crest, including epoccipitals 660 



Height of nasal horn core 72 



Length from tip of rostral to anterior border of orbit 600 



Length, anterior border of orbit to extremity of crest 1060 



Greatest depth of muzzle in front of nasal horn core 220 



Distance between antero-external edges of orbital rims 260 



Length of brow horn from superior border of orbit 310 



Circumference of brow horn near base 255 



Greatest diameter of orbit 110 



Greatest diameter (fore and aft) of parietal fontanelles 280 



Transverse diameter of parietal fontanelles 150 



Occipital condyle to extremity of crest 860 



The beautiful skeleton of Anchiceratops longirostris mounted at Ottawa (No. 8538, G.S.C.) 

 (PI. X, C) was found on the Red Deer River in the Edmonton formation, and except that it lacks a 

 skull, is complete to the tip of the tail. There were, however, a few diagnostic fragments of the 

 posterior portion of the crest which determined the genus and probably the species. A plaster skull 

 has been modeled from the type of A. longirostris which in all probability is essentially correct. 



