. The Deseado formation of Patagonia . romthe (hico del Chubut, west of Puerto Pisser, no less thanfourteen individuals being represented in our collection,three by skulls, and one by the major part of a skeletonwhich was found associated with the skull of Leontinia,but was determined as belonging to this species, by theduplication of the radius with a specimen having the radiusand lower jaws associated. The description of the genericcharacters is largely based on this skeleton. The threespecies are differentiated largely by their size, R. equinusbeing the largest, but as compared with R. piim
. The Deseado formation of Patagonia . romthe (hico del Chubut, west of Puerto Pisser, no less thanfourteen individuals being represented in our collection,three by skulls, and one by the major part of a skeletonwhich was found associated with the skull of Leontinia,but was determined as belonging to this species, by theduplication of the radius with a specimen having the radiusand lower jaws associated. The description of the genericcharacters is largely based on this skeleton. The threespecies are differentiated largely by their size, R. equinusbeing the largest, but as compared with R. piimulis it isnot only larger but much heavier built. The skull has been described under the generic discus-sion. In young individuals, the furrow in the incisors and 96 THE DESEADO FORMATION OF PATAGONIA canine is marked as a groove, later as a pit, and still lateris lacking altogether, as is the case in the specimen figured,for all three of my more complete specimens are old indi-viduals, as is also Ameghinos type. All the incisors show. Fig. 53. Dorsal view of skull—1/. natural size. the cingulum near the hase of the enamel. On account ofthe development of the cingulum on the inner anterior cor-ner of the premolars, these teeth are broadened out andoverhang the palate in a marked degree, and are also muchwider than long. Molar i is intermediate in character RHYNCHIPPUS EQUINUS 97 between the premolars and the succeeding molars, beingonly slightly rhomboidal in outline, while in the last twomolars the anterior external corner is markedly different individuals, the lower jaw varies greatly inheight, but this seems to me to be individual and sex varia-tion. The three incisors and the canine are subequal in
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Keywords: ., bookcentury1900, bookdecade1910, bookpub, booksubjectpaleontology
