DISCOVERY OF THE TITANOTHERES AND ORIGINAL DESCRIPTIONS 



219 



Ann. 



don). * * * Type D. montanus Marsh." The 

 term Anisacodon had been preoccupied by Anisacodon 

 Marsh, 1872, a genus of insectivores. 



Etymology. — Sis, double; kuvos, cone; 65ovs, tooth. 



Present determination. — See remarks under Anisaco- 

 don, above. 



FIRST NOTICE OF CANADIAN TITANOTHERES BY COPE, 1886 



Menodus angustigenis Cope, 1886 



Cf. Megacerops angustigenis, this monograph, page 482, 

 fig. 176, Ci 



Original reference. — Canada Geol. Survey 

 Kept., new ser., vol. 1, p. 81, 1886 (Cope, 

 1886.1). 



Subseguent references. — " Haplacodon 

 angustigenis," The Vertebrata of the 

 Swift Current River, II, p. 153, 1889 

 (Cope, 1889.1); On Vertebrata from the 

 Tertiary and Cretaceous rocks of the 

 Northwest Territory, I, p. 13, pi. 5, figs. 

 1, 2; pi. 6, figs. 2, 2a; pi. 7, figs. 1, la, la 

 [bis], 1891 (Cop, 1891.2). 



Type locality and geologic liorizon. — 

 Swift Current River, Assiniboia, Canada; 

 Cypress Hills beds, level not determined. 

 McConnell and Weston, collectors. 



Cope's cotypes. — Cope writes: 



This large mammal is represented by numer- 

 ous specimens. I select for present description 

 two maxillary bones from the same skull [fig. 

 176, A] [Cope, 1891.2, pi. 5, figs. 1, 2], each of 

 which contains the first [fourth] premolar and 

 the true molars; and two lower jaws from second 

 and third individuals [fig. 176, B]. One of these 

 [op. cit., pi. 7, figs. 1, la, la [bis], our fig. 176 C, 

 now regarded as the lectotype] consists of little 

 more than the symphysis. The other [op. cit., 

 pi. 5, fig. 2; pi. 6, figs. 2, 2a] includes part of 

 the symphysis and the left ramus, which con- 

 tains all the molar teeth except the first and last. 

 [See fig. 176.] 



Lectotype. — Of these semingly coequal 

 types or cotypes, which is to be regarded 

 as the lectotype? The one mentioned 

 first is "the two maxillary bones from 

 the same skull," but the mandibular 

 symphysis (op. cit., pi. 7, figs. 1, la, la 

 [bis]), from which the species evidently 

 takes its name (meaning narrow chin) , is 

 certainly to be selected as the lectotype. 



Specific cTiaracters. — Cope's description 

 is too long to quote here. He compared 

 Menodus angustigenis with " Symhorodon trigonoceras" 

 and other species and gave numerous measurements. 

 Among the chief characters noted are the contracted 

 shape of the mandibular symphysis and the square 

 outline of the molars. 



Etymology. — angustus, narrow; gena, chin. 



Present determination. — As defined from the lecto- 

 type the species is provisionally referred to Megacerops, 

 although its generic reference is uncertain. 



The maxilla with the dentition belongs to a very 

 different animal. It is apparently referable to Allops 

 sp. (See below.) The lower jaw appears to be 

 referable to Menodus cf . M. proutii. 



SPECIES DESCRIBED BY SCOTT AUD OSBORN IN 1887 



Menodus tichoceras Scott and Osborn, 1887 



Cf. Brontotherium tichoceras, this monograph, page 565 



Original reference. — Mus. Comp. Zoology BuL., vol. 

 13, No. 5, p. 159, text figs. 3, 2; 5, 2; 6, 2, 1887 (Scott 

 and Osborn, 1887.1). 



Figure 175. — Type (holotype) of Anisacodon montanus 



Yale Mus. 10022. A, Third right upper molar; B, fourth upper premolar and first and second molars; C, 

 alveoli of upper canines and incisors; Di, nasals, top view; Da, nasals, front view. All one-half 

 natural size. 



Type locality and geologic Tvorizon. — Big Badlands, 

 South Dakota; exact locality and horizon not recorded. 

 S. Garman, collector. 



Type.^&coit and Osborn describe the type as "a 

 large skull with the dentition complete, lacking the 

 upper part of the horns and the crest of the occiput." 

 Now in the Museum of Comparative Zoology at Cam- 

 bridge, Mass. (See fig. 177.) 



