TETRA PROTHOMO—THALASSICTIS. 671 
Tetraprothomo AmEGHINO, 1884. Primates, ? 
Filogenia, 1884, 381; Cont. Conocimiento Mamif. Fosil. Repub. Argentina, in Act. 
Acad. Nae. Cien., Córdoba, VI, 98, 1889. 
Hypothetical genus defined to show the probable evolution of man. ‘‘Cuarto 
antecesor del hombre." 
Tetraprothomo: rerp«-, four; mp@ros, first; +- Homo. 
Tetraprotodon (subgenus of Hippopotamus, FALCONER & CaAvTLEY), 1836. 
Ungulata, Artiodactyla, Hippopotamide. 
Asiatic Researches, Calcutta, XIX, pt. 1, 51, 1836. 
Tetraproctodon Gray, Cat. Carn., Pachyderm., & Edentate Mamm. Brit. Mus., 357, 
1869 (in synonymy). 
Species: Hippopotamus amphibius Linnzeus, from the Nile, Africa; and fourextinct 
species, H. antiquus Cuvier, H. minor Cuvier, H. medius Cuvier, and H. minimus 
Cuvier. 
Tetraprotodon: tetpa-, four; mp@ros, first; 00c v —ó00vzc, tooth. 
Tetraselenodon ScurossEn, 1886. Ungulata, Artiodactyla, Anoplothertidee. 
Morphol. Jahrbuch, Leipzig, XII, Ites Heft, 44-45, 134, Taf. vr, fig. 5, 1886. 
Type: Tetraselenodon kowalevskii Schlosser, from the Oligocene, 'Calcaire de Le- 
mandine', Dépt. Tarn-et-Garonne, France. 
Extinct. Based on an upper molar. 
Tetraselenodon: Tetpa-, four; 66A» r5, crescent; d6@v=dd0vs, tooth. 
Tetrastylus AMEGHINO, 1886. Glires, Chinchillidee. 
Bol. Aead..Nae. Cien. Córdoba, IX, 46-49, 1886. 
Type: Megamys (?) levigatus Ameghino, from the older Tertiary formations of 
Paraná, Argentina. 
Extinct. Based on one lower incisor and a portion of a jaw. 
Tetrastylus: tTetpa-, four; orvAos, pillar. 
Tetrodon AMmEGHINO, 1882.* Edentata, Megatheriidze (Scelidotheriidee). 
“Cat. Sec. de la Prov. de Buenos Aires en el Exp. Cont. Sud-Am. 4, 1882" 
(fide AMEGHINO) ; Cont. Conocimiento Mamif. Fósil. Repüb. Argentina, in Act. 
Acad. Nac. Cien., Córdoba, VI, 738-739, pl. xuiv fig. 8, 1889 (under Glossotherium 
bonwrense ). 
New name forthe ‘hybrid’ word Quatriodon Ameghino, 1881. ‘‘Mas siendo esto 
un nombre de composición hibrida, lo cambiaba . . . por el de Tetrodon.’’ 
Name preoccupied by Tetrodon Linnzeus, 1766, a genus of Pisces. 
Extinct. 
Tetrodon: rerpa-, four; 6d6@v—=d6o0vs, tooth. 
Thalacomys (see Thylacomys). Marsupialia, Peramelid:e. 
Thalarctos (subgenus of Ursus) Gray, 1825. — Glires, Ursidze. 
à Sara : T . ‘ ses 
Thomson’s Ann. Philos., XXVI, 62, July, 1825; List Spec. Mamm. Brit. Mus. 
b ? , J? 3 ? 
pp. xxi, 73, 1843 (genus). 
Thalassarctos Gray, Thomson's Ann. Philos., XXVI, 339, Nov., 1825 (raised to 
generic rank). 
Thalassarctus GLoGER, Hand- u. Hilfsbuch Naturgesch., pp. xxviii, 54, 1841. 
3 ? , , 
Type: Ursus maritimus Phipps, from Spitzbergen. 
Thalarctos: Contraction of 0tAa66«, sea; &pkroc, bear. 
Thalassictis NorpMANN, 1848-52.1 Glires, Viverridz. 
, 3 
NOoRDMANN, in Gervais! Zool. et Paléont. Francaises, 1° éd, I, 120, 1848-52; 2° éd. 
3 E 3 , , , 
221—222, pl. xxi fig. 3, 1 text fig., 1859. 
** Thallasictis NORDMANN, Palaeont. Suedrusslands, 149, 1858" (fide WATERHOUSE 
MS. ). 

* Erroneously given as Ameghino, ‘1881,’ by C. O. WarEnnovsE, Index Zool., 370, 1902. 
T Date erroneously given as ‘1839’ by Trourssarr, Cat. Mamm., new ed., 320, 1898. 
