Marsh — Principal Characters of the Protoceratidoe. 175 



strongly closed behind, all suggest an ally of Protoceras, but 

 the parietal ridges are here elevated into distinct crests, and are 

 without horns. 



"This skull when complete was about six inches in length. 

 The distance from the front of the nasals to the junction of 

 the parietal crests is about four inches and a half. The space 

 occupied by the last three premolars and the true molars is 

 about two and one-half inches." 



In a later notice, a second more perfect specimen from the 

 same horizon was described,* the main points stated being as 

 follows : 



" The brain was comparatively well developed, and an 

 unusually large part of the cerebral lobes was covered by the 

 parietals. The frontal region of the skull between the orbits 

 was more or less concave. The antorbital depressions extend 

 well forward. There is a diastema between the upper canine 

 and the first premolar, and between the first and second pre- 

 molars. The canines above and below are small. The first 

 lower premolar appears to be wanting. The second and third 

 premolars have secant crowns, much elongated fore and aft. 

 The postglenoid process is quite small, but the paroccipital is 

 large and robust. The lower jaw has a very short coronoid 

 process, and the condyle is sessile. The angle of the jaw is 

 well rounded and somewhat dependent." 



This second specimen proves to be distinct from the type, 

 and is here recorded as a new species, Calops consors. The 

 skull, which is in good preservation, is represented on Plate 

 VII, figures 1 and 2. These two views exhibit the main 

 features of the skull in the genus Galops. The most striking 

 difference between this specimen and the type is the position 

 of the orbit, which in the latter is entirely behind the molar 

 series, as in Protoceras, while in the specimen here figured, as 

 shown in Plate VII, nearly half the orbit is in front of the 

 posterior end of this series. 



The Dentition of Calops. 

 The teeth of Calops correspond essentially with those of 

 Protoceras, being of the same early ruminant type, with the 

 characteristic, short-crowned, selenodont molar series, and 

 apparently the same dental formula. In the female skull 

 represented on Plate VII, figure 1, most of the teeth are seen 

 in position. There were no upper incisors. The canine was of 

 moderate size, and placed well back of the premaxillary suture. 

 The first premolar is small, with a compressed crown and two 

 roots, and is situated somewhat behind the middle of the 



*This Journal, vol. xlviii, p. 273, September, 1894. 



