MONOCLONIUS. 



81 



Monoclonius fissus Cope. 1889. 



Type (No. 3988, American Museum of Natural History) consists of poorly preserved pterygoid. 



Original description on page 717, vol. 23, Am. Naturalist, 1889. 

 Nopcsa, F. Baron, Foldtani Kozlony, Budapest, 1901, vol. 31, p. 270. 

 Osborn, H. F., Contr. Canadian Pal., vol. 3 (quarto), pt. 2, 1902, pp. 14, 20. 



Founded on a right pterygoid mistaken by Cope for a squamosal (No. 3988, American 

 Museum of Natural History). This bone is very incomplete. I shall only quote Cope's original 

 description and give figures of the type, since 

 the species is based on very insufficient and 

 unsatisfactory material. 



Founded on a squamosal bone of an individual of much 

 smaller size than those above described [it. crassus, recur- 

 mcornis, and sphenocerus]. The suture with the parietals is 

 relatively shorter than in the M . crassus, occupj'ing only the 

 distal third of the margin. The plate anterior to the trans- 

 verse suture for the quadrate is more nearly in one plane, is 

 wider in relation to its length, and has a squamosal sutural 

 surface and a transverse groove not seen in the M . crassus. 

 The excavation posterior to the process which joins the 

 quadrate is deeper. External border mostly lost. Total 

 length, 180 mm. ; length in front of quadrate suture, 50 mm. ; 

 width in front of same, 87 mm.; width at postquadrate con- 

 cavity, 62 mm. 



4 



Fig. S9. — A, External view of right pterygoid, type of Monoclonius 

 fissus Cope, No. 3988, American Museum of Natural History; B, 

 internal view of same, qs, Surface for quadrate; a, surface for 

 pterygoid process; ec, eustachian canal (?). One-fourth natural 

 size. 



Fig. 89 shows the extremely fragmentary 

 and unsatisfactory nature of the type of this 



species. It also indicates the diminutive size of the animal to which it pertained when compared 

 with the more gigantic forms from the Laramie of Converse County, Wyo. Owing to the frag- 

 mentary nature of the type, I am quite unable to add anything additional to the specific char- 

 acters given by Cope, and the species must remain practically as a nomen nudum, which it 

 would not be amiss to relegate to the paleontological wastebasket. 



Monoclonius recurvicornis Cope. 1889. 



Type (No. 3999, American Museum of Natural History) consists of portions of skull, including frontal and nasal horn cores. 



Original description on page 716, vol. 23, of American Naturalist. 

 Hatcher, J. B., Am. Naturalist, vol. 33, 1896, p. 113. 

 Lambe, L. M., Contr. Canadian Pal'., vol. 3 (quarto; , pt. 2, 1902, p. 68. 

 Nopcsa, F. Baron, Foldtani Kozlony, Budapest, 1901, vol. 31, p. 270. 

 Osborn, H. F., Contr. Canadian Pal., vol. 3 (quarto), pt. 2, 1902, pp. 14, 20. 



The type of the present species consists of the occipital region of the skull, both supra- 

 orbital horn cores, a portion of the frontals, the nasal horn core coossified with a fragment of 

 the nasals, a fragment of the jugal, and a fragment of the parietal showing about 10 inches of 

 the periphery with two epoccipital bones in place. 



The specimen was discovered by Prof. E. D. Cope in 1876, in a bluff on the north side of 

 the Missouri River, nearly opposite the mouth of Dog Creek, in Montana. According to Cope, 

 the geological horizon was near the base of the Judith River beds as these are represented at 

 this locality. 



The material upon which the present species was based was first described in great detail, 

 without, however, being named by Cope, in volume 3 of the Bulletins of the U. S. Geological 

 and Geographical Survey of the Territories under Hayden, pages 588-594. His description 

 was as follows: 



1. Cranial bones of a dinosaurian. — A number of the bones of the skull of a large dinosaurian reptile were found in the 

 second bed of lignite above the lower bed of sandstone represented in fig. 3 as belonging to the Judith River beds, or Creta- 

 ceous No. 6. The locality where they are found is on the north side of the Missouri River, nearly opposite to the mouth 

 of Dog Creek. The bones were lying in immediate contact, and with them was found a fragment consisting of two teeth and 

 HON xlix — 07 6 



