RIBODON—ROMEROLAGUS. 611 
Ribodon—Continued. 
Ribodon: Contraction of AUA(dyr), lit. with a noise; 66@v—=ddo0ts, tooth. 
“pvUPSyv, adverbe ayant la méme signification que 6Vdyr ou Avddr, lisse, 
coulant, fluide, etc. . . . j'ai employé ce nom à cause de l'émail des molaires à 
surface trés polie de sorte que ces dents glissent des doigts." (AmMEGHINO, in 
epist. ) 
Ricardolydekkeria Amrcuino, 1901. Ungulata, Amblypoda, Pantolambdide. 
Bol. Acad. Nac. Cien. Córdoba, XVI, 397, July, 1901 (sep. p. 51). 
Species: Ricardolydekkeria prerupta Ameghino, and R. profunda Ameghino, from 
the ‘Cretaceous’ of Patagonia. 
Extinct. 
Ricardolydekkeria: In honor of Richard Lydekker, 1849—, author of Catalogues 
of Fossil Mammals, Birds, and Reptiles in the British Museum, ‘Geographical 
History of Mammals,’ ‘Royal Natural History,’ and numerous other works on 
mammals; co-author of ‘Manual of Paleontology,’ 1889; ‘Mammals, Living 
and Extinct,’ 1891. 
Ricardowenia AMEGHINO, 1901. Ungulata, ? ( Carolozittelidze). 
Bol. Acad. Nac. Cien. Córdoba, XVI, 390, July 1, 1901 (sep. p. 44). 
Type: Ricardowenia mysteriosa Ameghino, from the ‘Cretaceous’ of Patagonia. 
Extinct. 
Ricardowenia: In honor of Sir Richard Owen, 1804-92, professor of compara- 
tive anatomy at the Royal College of Surgeons, 1834-56; a director of the 
British Museum, 1856-84; author of ‘Odontography,’ 1840-45, ‘Anatomy of 
Vertebrates,’ 1866-68, and a long list of brilliant zoological monographs. 
Rigoon GisrEL, 1848. Fer, Pinnipedia, Phocid:e. 
Naturgesch. Thierreichs für hóhere Schulen, p. x, 1848 (under Pelagius). 
New name for Pelagios F. Cuvier, 1824 ( — Pelagius F. Cuvier, 1826), which is pre- 
occupied by Pelagia Péron, 1809, a genus of Acaleph:e. 
Antedated by Monachus Fleming, 1822; and by Pelagocyon Gloger, 1841. 
Rigoon: pip óc, to be cold, to shiver—evidently from the animal's aquatic 
habits, but the name is not very appropriate for a genus of tropical seals. 
Risia (subgenus of Antilope) LauRILLARD, 1841. Ungulata, Artiodactyla, Bovidee. 
D'Orbigny's Dict. Univ. Hist. Nat., I, 625-626, 1841 (art. ‘Antilope’). 
Species, 3: Antilope picta Gmelin, from India; A. furcifer H. Smith, from the 
plains of the Missouri River; and A. palmata H. Smith, from Mexico. 
Risia: Sanskrit ris’ya, or rishya (from Hindu rojh, raksh? lightning), a name 
applied to Antilope picta in the Amera Cosha, and in the Indian Sacred Vol- 
ume, chap. xxiv. (H. Surrg, Griffith's Cuvier, IV, 363, 1827.) 
Rithrodon (see Reithrodon). Glires, Murid:e, Cricetinze. 
Rityna (see Rytina). Sirenia, H ydrodamalid:e. 
Rizaena (see Ryzaena). Feree, Viverrid:e. 
Robus (see Kobus). Ungulata, Artiodactyla, Bovidee. 
Rodiotherium AmrGcHino, 1895. Ungulata, Ancylopoda, Leontiniidee. 
Bol. Inst. Geog. Argentino, XV, cuad. 11-12, p. 653, 1895 (sep. p. 53). 
Type: Rodiotherium armatum Ameghino, from the Pyrotherium beds in the inte- 
rior of Patagonia. 
Extinct. Based on an imperfect mandibular symphysis. 
Rodiotherium: Anagram of Diorotherium Ameghino, 1891. 
Romerolagus Merriam, 1896. Glires, Leporide. 
Proc. Biol. Soc. Wash., X, 173-174, fig. 33, Dec. 29, 1896. 
Type: Romerolagus nelsoni Merriam, from Mt. Popocatepetl, Mexico (alt. 3,350 
meters). 
