DISCOVERY OF THE TITANOTHERES AND ORIGINAL DESCRIPTIONS 



225 



Allops serotinus Marsh, 1887 

 Cf. Allops serotinus, this monograph, page 515 

 Original reference. — Am. Jour. Sci., 3d ser., vol. 34, 

 p. 331, October, 1887 (Marsh, 1887.1). 



Type locality and geologic horizon. — Quinn Draw, 

 South Dakota, "near the top of the Brontotherium 

 beds," Chadron formation {TitanotTierium zone). 



Figure 184. — Type (liolotype) skull of Allops serotinus 

 After Marsh. Nat. Mus. 4251. One-seventh natural size. 



Type. — "A well-preserved skull and various other 

 remains." U. S. Nat. Mus. 4251. J. B. Hatcher, 

 collector. (See fig. 184.) 



Specific characters. — Not separated from generic 

 characters in original description. 



Etymology. — serotinus, from sero{1), to bind, connect; 

 possibly because the characters appeared to be more 

 or less annectant with those of other species. 



Present determination. — The species is valid. It is 

 described on page 515. 



CANADIAN SPECIES DESCRIBED BY COPE IN 1889 

 Haplacodon Cope, 1889 



Cf. Allops, this monograph, page 506 

 Original reference. — Am. Naturalist, vol. 23, p. 153, 

 March, 1889 (Cope, 1889.1). (See p. 202.) 



Type species. — Menodus angustigenis Cope. The 

 genus was founded on the characters of one of the 

 several "types" of Menodus angustigenis, namely, a 



maxilla containing the fourth upper premolar and the 

 three molars. 



Generic characters. — Cope writes: 



It differs from all the genera of the Menodontidae in the 

 presence of but a single internal cusp of the first (posterior) 

 superior premolar, a fact which renders it highly probable 

 that the premolars which precede it in the maxillary bone 

 were similarly constituted. It differs from all other genera of 

 Lambdotheriidae and also from Diplacodon, to which it is 

 allied, in the presence of but two inferior incisors on each side. 

 It is not certain whether it possesses horns or not. 



Comparative measurements of the type of "Haplacodon" Cope, in 

 millimeters 



M'-m' 



P', ap. by tr__ 

 M', ap. by tr_ 

 M\ ap. by tr_ 

 M^, ap. by tr_ 



187 

 38X62 

 50X52 

 66X62 

 65X62 



169 

 35X51 

 45X51 

 61X61 

 60X61 



Etymology. — awXoos, simple; aKri, cone; 65ous, tooth; in 

 allusion to the "single internal cusp" of the fourth 

 upper premolar. 



Present determination. — The upper teeth agree 

 closely in general characters with those of Allops and 

 are intermediate in size between Allops walcotti and 

 Allops marshi. 



A2 



A3 



Figure 185. — Type of Menodus selwynianus 



Coossifled nasal. Ai, Left side; Aj, upper side; A3, under side. Three-eighths 



natural size. 



Menodus selwynianus Cope, 1889 



Cf. Diploclonus selwynianus, this monograph, page 502 

 Original reference. — Am. Naturalist, vol. 23, p. 628, 



July, 1889 (Cope, 1889.2). 



Subsequent reference. — On Vertebrata from the 



Tertiary and Cretaceous rocks of the Northwest 



Territory, I, p. 17, pi. 5, figs. 3, 3a, 3b, 1891 (Cope, 



1891.2). 



