. Descriptions of twenty-six new species of North American mammals. Mammals North America. 24 KORTH AMERICAN FAUNA. [No. 4. orbits it spreads out more abruptly, and the postorbital process of the squamosal is more promiueut, so that the orbital and temporal fossae are more sharply separated. A broad depression occupies the posterior part of the frontals. The audital bullae are large and high, but are less inflated laterally than in gapperi. The zygomatic arches are somewhat expanded upward at the point of junction of the jugal with the zygo- matic process of the maxillary, showing a tendency t
. Descriptions of twenty-six new species of North American mammals. Mammals North America. 24 KORTH AMERICAN FAUNA. [No. 4. orbits it spreads out more abruptly, and the postorbital process of the squamosal is more promiueut, so that the orbital and temporal fossae are more sharply separated. A broad depression occupies the posterior part of the frontals. The audital bullae are large and high, but are less inflated laterally than in gapperi. The zygomatic arches are somewhat expanded upward at the point of junction of the jugal with the zygo- matic process of the maxillary, showing a tendency toward the forma- tion of the vertical lamella seen in Phenacomys and the lemmings. Dental characters.—The molar series are considerably larger than in skulls of gapperi of the same size, but are not so large as in Phenacomys. The last lower molar is slightly broader posteriorly than anteriorly (con- trary to the rule in Evotomys) and is broadest in the middle. It con- sists of three transverse loops, all of which are closed. The re-entrant angles of the inner side are very deep 5 those on the outer side are cor- respondingly shallow. The front lower molar has the usual number of loops and triangles. The anterior loop is directed straight forward and communicates broadly with the adjoining triangles on each side, leaving one external and two internal closed (or nearly closed) triangles and a posterior loop. The upper molars present no noteworthy peculiarities. All of the molars in both jaws are rooted, each having two long and well-formed roots, resembling those of Phenacomys^ except that they are not closed at the bottom. (See fig. 3.) They may be considered as intermediate between those of Evotomys rutilus and Phenacomys, a. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Merriam, C. Hart (Clinton Hart),
Size: 1270px × 1968px
Photo credit: © Paul Fearn / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1890, bookpublisherwashingtongovtprin
