136 THE CERATOPSIA. 



The nasal Tiom core is very short and stout, rising but little above the superior surface 

 of the nasals and projecting a little in front of the anterior border of the superior processes 

 of the premaxillaries, which formed its chief support. Although in the present specimen the 

 suture between the nasal horn core and the nasals is closed, it is still distinguishable, and the 

 nasal horn core is seen to have originated from a center of ossification distinct both from the 

 nasals and the premaxillaries. In a second specimen belonging to a younger individual, which 

 I shall consider as a cotype, a No. 4805, U. S. National Museum, found on the same horizon 

 and only a few feet from the type, the nasal horn core is disarticulated and the sutural surfaces 

 at the base for contact with the premaxillaries and nasals are very distinct. The form and 

 characters of this nasal horn core 'are well shown in fig. 115. 



The jugal is especially characteristic in the present species. The inferior process, instead 

 of descending vertically beneath the orbit as in most other species of the Ceratopsia, is directed 

 downward and backward at an angle of about 45°, and the distal end is produced far back of 

 the posterior border of the orbit. The posterior border of the inferior process of the jugal is 

 regularly but gently convex, the anterior concave. 



The external surface of the maxillary is very rugose and the bone in this region appears 

 to have been diseased. It is not possible to trace with accuracy the suture between the maxil- 

 lary and the jugal. 



On the parietal crest, just posterior to the supratemporal fontanelle, the squamosal presents 

 two indentations, which may perhaps be interpreted as malformations resulting from injuries. 

 One of these, the anterior, is very pronounced, the bone being completely perforated. I am 

 inclined to consider this as due to some injury received during the life of the animal rather 

 than as a persistent structural character of specific importance. 



Principal measurements of the type. 



Mm. 



Greatest length of skull 1 , 934 



Distance from posterior border of orbit to posterior extremity of squamosal 963 



Distance from anterior border of orbit to extremity of nasal horn core 520 



Distance from anterior border of orbit to extremity of rostral 833 



Distance from extremity of rostral to extremity of quadrate 1, 025 



Height of extremity of supraorbital horn core above inferior margin of maxillary 1, 154 



Distance in straight line from apex of supraorbital horn core to superior border of orbit 740 



Length of supraorbital horn core measured along posterior surface 940 



Length of supraorbital horn core measured along anterior surface ... 690 



Antero-posterior diameter of supraorbital horn core at base . 310 



Transverse diameter of supraorbital horn core at base, somewhat reduced by crushing 150 



Greatest circumference of supraorbital horn core at base 840 



Circumference of supraorbital horn core at middle. 380 



Circumference of supraorbital horn core at apex 128 



Thickness of postfrontal back of orbit 220 



Greatest length of squamosal - ... 950 



Greatest expanse of squamosals, estimated 1, 000 



Greatest expanse of jugals, estimated j . . 500 



Diameter of occipital condyle. .... . . 106 



DESCRIPTION OF COTYPE [PLESIOTYPE]. 



On the same horizon, and at a distance of about 10 feet from the type of the present species, 

 remains of a second skeleton were found, which I shall consider as the cotype [plesiotype] of 

 the present species, although it possesses some characters which might be considered as of 

 specific importance. The remains of this second specimen consist of a right dentary with 

 the surangular and coronoid, a portion of the left surangular, the occipital condyle, nasal horn 

 core, an imperfect pterygoid, several epoccipitals, and some other portions of the skull and 

 skeleton not now accessible. 



a More properly a plesiotype. This is a term defined by Schuchert and Buekman (Science, n. s., vol. 21, June 9, 1905, p. 900) as follows: 

 "Plesiotype. Any specimen identified with an already described and named species, but not selected by the nomenclator himself." The 

 word is further defined (p. 899) as referring to " material upon which supplementary descriptions of species are based."— R. S. L. 



