158 



TITANOTHERES OF ANCIENT WYOMING, DAKOTA, AND NEBRASKA 



(Millersville) is about 10 miles distant from that of 

 the holotype (Church Buttes), but the geologic level 

 is believed to be identical, namely, Bridger B 1 . 



Etymology. — paludosus, marshy, dwelling in the 

 marshes, probably because the remains were found in 

 one of the supposed "ancient lake basins." 



Present determination. — Palaeosyops paludosus Leidy 

 is a valid species, but the "P. paludosus" of other 

 authors refers to related species of more recent geologic 

 age (P. major, P. leidyi, P. rolustus). 



Palaeosyops major Leidy, 1871 



Cf. Palaeosyops major, this monograph, page 321 

 Original reference. — Acad. Nat. Sci. Philadelphia 



Proc, 1871, p. 229 (Leidy, 1871.1). 



Subsequent reference. — Leidy, Extract vertebrate 



faima of the Western Territories, p. 45, pi. 20, fig. 



8, 1873 (Leidy, 1873.1). 



Figure 89. — Leidy's type (.holotypej of Palaeosyops major in 

 the collection of the Academy of Natural Sciences of Phila- 

 delphia 



Part of the right ramus of a lower jaw. After Leidy, 1873. One-half natural size. 

 "The specimen is somewhat swollen and altered from disease and is one of those 

 upon which the species was first indicated. Discovered by Dr. Carter at Grizzly 

 Buttes." (Leidy.) 



Type locality and geologic liorizon. — Grizzly Buttes, 

 Bridger Basin, Wyo.; Palaeosyops paludosus-OroTiip- 

 pus zone (Bridger B 2 or B 3). Dr. J. Van A. Carter, 

 collector. 



Holotype. — "A jaw fragment with the retained 

 fragments of the true molars." This type is now in 

 the collection of the Philadelphia Academy of Natural 

 Sciences. (See fig. 89.) 



Characters (Leidy). — Size apparently "much larger 

 than P. paludosus." 



The true molars occupied a space of 4J^ lines. The last 

 molar measured IJ^ inches fore and aft and an inch trans- 

 versely in front. " 



In his "Extinct vertebrate fauna" of 1873 (1873.1, 

 pp. 45, 46) Leidy gives a fuller description of the very 

 imperfect holotype and figures it on Plate 20, Figure 

 8. He believed the jaw specimen to be 

 in some degree abnormal in form, due to inflammation or 

 some other affection connected with the second molar tooth. 



* * * In its proportions the jaw, in a normal condition, 

 would appear to be of more robust character than in Palaeo- 

 syops paludosus. * * * In its present state the base is 

 more convex fore and aft than in the latter, and the alveolar 

 border more ascending posteriorly. 



The remains of the molar fangs at the entrance of the alveoli 

 appear to indicate teeth of the same form and construction as in 

 Palaeosyops paludosus, for which reason the fragment was 

 referred to the same genus. The true molars appear to have 

 occupied a space of 4^ inches, though this is probably some- 

 what exaggerated, as the interval occupied by the last inter- 

 mediate molar appears proportionately somewhat too large. 

 The crown of the last molar, which was clearly trilobate as in 

 Palaeosyops paludosus, had an antero-posterior diameter of 2 

 inches. 



Leidy's paratype, "consisting of the left ramus of the 

 lower jaw, containing six molar teeth," was obtained 

 by Doctor Carter "in Dry Creek Canyon, 40 mUes 

 from Fort Bridger" (Bridger Basin, Bridger C) and 

 together with a second similar specimen from the 

 same locality is described by Leidy (1873.1, p. 46, pi. 

 23, fig. 1; second specimen, fig. 2). 



The holotype, it is important to note, is from the 

 low level (probably Bridger B 2) of Grizzly Buttes, 

 but Leidy's paratype, which has the characters of the 

 more progressive Palaeosyops leidyi Osborn, is from 

 the higher level (Bridger C) of Dry Creek. The 

 paratype is thus certainly not conspecific with the 

 holotype. 



Osborn's neotype. — In order to supplement the 

 characters of Leidy's imperfect holotype, the present 

 writer has selected as a neotype a lower jaw (fig. 

 268, C) with dentition (Am. Mus. 12181) from Cotton- 

 wood Creek and from about the same level (B 3) 

 as the holotype, with which it agrees closely. (See 

 Chap. V.) 



Etymology. — major, in allusion to the larger size as 

 compared with P. paludosus. 



Present determination. — The species P. major is 

 believed to be a valid one. 



Canis montanus Marsh, 1871 

 Cf. Canisf marshii Hay, below {Palaeosyops major?), page 178 



Original reference. — Am. Jour. Sci., 3d ser., vol. 2, 

 p. 123, August, 1871 (Marsh, 1871.2). 



Type locality and geologic liorizon. — Grizzly Buttes, 

 Bridger Basin, Wyo.; Palaeosyops paludosus-Oro- 

 hippus zone (Bridger B, probably B 2). 



Marsh's cotypes. — "A last upper premolar tooth in 

 good preservation, a canine, wanting most of the 

 crown, and a number of the larger bones of a skeleton, 

 all apparently of the same species, but pertaining to 

 three individuals, differing somewhat in size " (Marsh). 

 Of these materials the "last upper premolar" (first 

 lower premolar) alone is described and measiu'ed, and 

 it is also the first specimen mentioned. It should 

 therefore be taken as the lectotype (Yale Mus. 11770). 



Characters. — "The last upper premolar * * * 

 is robust, has a short compressed crown. The princi- 

 pal cusp is conical, with subacute edges, the anterior 

 being about twice the length of the posterior. Behind 



