SYSTEMATIC REVISION IQ 



"The malar or quadratojugal bone is protuberant at the canthus oris and 

 projects laterally beyond the mandible at its posterior part. It also pro- 

 jects beyond the extremity of the quadrate bone. This border is continued 

 as that of the external base of the horn, but the portion which belongs to 

 this element is soon distinguished from the superior element (squamosal) 

 which composes the horn, by a groove. This groove is decurved and bounds 

 the apex of the element, which is a decurved, low tuberosity. The horn is 

 produced backwards in a horizontal plane, forming a long, flat triangle 

 which contracts gradually with straight sides. The apex is narrowed, obtuse, 

 and a little incurved. Near and at the extremity the horn is flat above and 

 convex below. 



"The mandibular quadrate cotylus consists of two fossae, which together 

 form an approximate figure co , of which the internal fossa is the smaller, 

 and opens internally. The external one is nearly transverse. The superior 

 border of the ramus posteriorly is straight. The greater part of the superior 

 aspect is occupied by a huge fossa which opens upwards. 



"It is uncertain whether the horns meet at an entering angle on the 

 middle line posteriorly or not, but the width of the base of the horn indi- 

 cates that such is the case. The extremity of the muzzle is depressed and 

 is broadly rounded. 



"The external surface of the skull is sculptured in the form of fossae so 

 distributed that the narrow ridges separating them do not form straight 

 lines, except in a few places on the superior face of the horn. This sculpture is 

 strongly impressed and is of medium coarseness. It extends on the inferior 

 face of the quadratojugal (?) posterior to the quadrate, and on the infe- 

 rior side of the horn at the edges. It is most extended below from the interior 

 edge, and for the terminal inch of the horn is as well marked as on the supe- 

 rior face. Elsewhere the sculpture of the inferior side passes into punctse 

 before disappearing. A groove marks the superior boundary of the maxillary 

 bone, which divides when it reaches the superior surface. One branch 

 descends behind the nostril, the other passes transversely across the lach- 

 rymal bone and shallows out before reaching the middle line of the muzzle. 

 The mandible is even rougher than the superior surfaces, and has a longi- 

 tudinal groove below the dental line to near the symphysis, where it runs 

 out on the alveolar edge. The internal and external sides of the mandible 

 posteriorly are smooth. On the malar and other facial bones there are four 

 fossse in 9 or lo mm. 



"The atlas is peculiarly flattened above, the neural arch being a tube, 

 without neural spine. Its anterior tubular prolongation is not long and is 

 deeply notched below. The condyloid fossse are widely spread transversely 

 and nearly flat, except that their surface is carried forwards on the neural 

 tube. They are well separated below. There is a strong hypapophysial 

 keel, which diminishes and runs out anteriorly. There are prezygapophysial 

 facets, but the postzygapophyses exist. Their superior edge is, however, 

 carried posteriorly to form the sides of the huge embracing zygantrum. 

 These side processes, which I will call zygantropophyses, extend as far pos- 

 teriorly as above the posterior end of the centrum of the axis, embracing 

 almost the whole of the neural arch. There is another short median supe- 

 rior process, which notches the extremity of the zygosphen. The side of 

 the atlas between the postzygapophysis and the condyloid facet is wrinkled, 

 and the inferior face finely punctate. 



