LEPTARCTUS—LEPTOCLADUS. 871 
Leptarctus—Continued. 
Type: Leptarctus primus Leidy, from the Miocene of the Bijou Hills, South 
Dakota. 
Extinct. ‘‘ Founded on a single specimen of an upper molar tooth." 
Leptarctus: Aezróc, small, slender; &pKros, bear. 
Leptauchenia Lrrpy, 1856. Ungulata, Artiodactyla, Agriochceride. 
Proc. Acad. Nat. Sci. Phila., 1856, 88. 
Type: Leptauchenia decora Leidy, from the Oligocene of the Valley of White 
River, Nebraska or South Dakota. 
Extinct. Based on ‘fragments of upper and lower jaws, with teeth.’ 
Leptauchenia, small, slender; -+-Auchenia. 
Lepthyzena LvpEkkEn, 1884. Fere, Viverrid:e. 
Palzont. Indica (Mem. Geol. Surv., India), ser. 10, II, pt. vr, 312-313, pl. xiv, 
figs. 8-9, Jan., 1884. 
Type: Ictitherium sivalense Lydekker, from the Siwaliks of Asnot, Punjab, India. 
Extinct. Based on ‘two fragments of the rami of opposite sides.’ 
Lepthyena: Aezrós, small, slender; + Hyena. 
Leptictis Lrmpy, 1868. Insectivora, Leptictide. 
Proc. Acad. Nat Sci. Phila., 1868, 315-316. 
Type: Leptictis haydeni Leidy, from the Oligocene (White River) of South 
Dakota. 
Extinct. Based on ‘a nearly entire skull, devoid of the lower jaw.’ 
Leptictis: Aezrós, small, slender; “Kris, weasel. 
Leptobos Ritrmeyer, 1877. Ungulata, Artiodactyla, Bovidee. 
* Abhandl. Schweiz. Palaeont. Gesellsch., IV, DISS deel. VIVI 91/59 Ve 13, 
1878" (fide ArsroN, Zool. Record for 1877, XIV, Mamm., p. 6, 1879; ibid., 
for 1878, XV, Mamm., p. 20, 1880). 
Species, 3; from the Pliocene and Pleistocene: Leptobos falconeri Rütimeyer, from 
the Siwalik Hills, India; L. frazeri Rütimeyer, from the Narbada Valley, 
India; and L. strozzii Rütimeyer, from the Val d' Arno, Italy. 
Extinct. 
Leptobos: Aezrós, small, slender; + Bos. 
Leptoceros (subg. of Antilope) WAaGNER, 1844. Ungulata, Artiodactyla, Bovid:e. 
Suppl. Schreber’s Siiugthiere, IV, 422—423, 1844. 
Type: Antilope leptoceros F. Cuvier, from Sennar, northeast Africa. 
Name preoccupied by Leptocerus Leach, 1817, a genus of Neuroptera. 
Leptoceros: ÀAezrósc, small, slender; Képas, horn. 
Leptochoerus Lripy, 1856. Ungulata, Artiodactyla, Suide. 
Proc. Acad. Nat. Sci. Phila., 1856, 88. 
Type: Leptochoerus spectabilis Leidy, from the Oligocene of the Bad Lands of 
Nebraska (South Dakota). 
Extinct. Based on ‘‘a small fragment of the lower jaw . . . containing two 
molar teeth." ! 
Leptochoerus: Aerros, small, slender; yozposc,hog—in allusion to the lower molars. 
Leptocladus Owen, 1871. Marsupialia, Amphitheriidee. 
Mesozoic Mamm., in Mon. Palseontograph. Soc., XXIV [No. 5], 53-54, pl. rr, 
figs. 4, 4a, 1871 (provisional name). 
Type: Leptocladus dubius Owen, from the Purbeck of Durdlestone Bay, Swanage, 
Dorsetshire, England. 
Extinct. Based on a left mandibular ramus. 
Leptocladus: A&zrós, slender; «Aoc, ramus—in allusion to the lower jaw. 
