126 EXTINCT AND VANISHING MAMMALS 



by him Clidomys, Speoxenus, and Spirodontomys, is still to be 

 made out. These three are represented by teeth and a few 

 other fragments almost all of which were in a hard breccia and 

 may be of greater age than the cave material of Puerto Rico. 

 The teeth indicate stages of development that may be ancestral 

 to such a condition as found in Heptaxodon, but as yet only a 

 preliminary account has been published (Anthony, 1920b). 



Family DINOMYIDAE: Giant Rodents 



"QlJEMl" OF OVIEDO 

 QUEMISIA GRAVIS Miller 



Quemisia gravis Miller, Smithsonian Misc. Coll., vol. 81, no. 9, p. 23, Mar. 30, 1929 



("The crooked cave near the Atalaye plantation," St. Michel, Haiti). 

 FIGS.: Miller, 1929a, pi. 4, figs. 2, 3. 



ELASMODONTOMYS OBLIQUUS Anthony 



Elasmodontomys obliquus Anthony, Ann. New York Acad. Sci., vol. 27, p. 199, Aug. 9, 



1916 ("Cueva de la Ceiba, near Utuado, Porto Rico"). 

 FIGS. : Anthony, 1916, pis. 13, 14 (skull and teeth); 1918, figs. 25-37 (skull and other 



skeletal parts). 



Since almost nothing beyond skeletal remains of these two 

 species is known, and because they stand evidently in close 

 relationship, they may be considered together. In general 

 size they were about alike and probably were nearly as big as a 

 paca, Quemisia, inhabiting Hispaniola, and Elasmodontomys, 

 the adjacent island of Puerto Rico. Miller, in describing the 

 former, expresses his conviction that it is the animal called 

 "Quemi" by Oviedo in his account of the animals of Hispaniola, 

 published slightly more than a quarter of a century after the 

 discovery. 



These two mammals, the largest of the extinct rodents known 

 from their respective islands, are hystricomorphs with rela- 

 tionships to the South American Dinomyidae and Chinchilli- 

 dae, but since there is no evidence that they had developed 

 leaping modifications, it may be better to regard them as 

 members of the former, as proposed by Miller and Gidley. 

 In both, the enamel pattern of the cheek teeth consists of 

 diagonally transverse folds running nearly across each tooth, 

 so as to present a laminate appearance, with five enamel 

 ridges to each. In Quemisia, according to Miller (1929a), the 



