. Catalogue of the mammals of western Europe (Europe exclusive of Russia) in the collection of the British Museum. riG. 8. Siirex araneits: Anteriur teeth in prolile. X 5. and posterior borders sub-equal, slightly longer than anterior border. Cusp rounded on antero-external face, squarely truncate postero-internally atong line connecting antero-internal and postero-external corners of crown. The region behind this line is occupied by a flattened or somewhat concave, nearly horizontal crushing surface opposed during mastication to second and third lobes of lower incisor (1st and 2nd upper unicu
. Catalogue of the mammals of western Europe (Europe exclusive of Russia) in the collection of the British Museum. riG. 8. Siirex araneits: Anteriur teeth in prolile. X 5. and posterior borders sub-equal, slightly longer than anterior border. Cusp rounded on antero-external face, squarely truncate postero-internally atong line connecting antero-internal and postero-external corners of crown. The region behind this line is occupied by a flattened or somewhat concave, nearly horizontal crushing surface opposed during mastication to second and third lobes of lower incisor (1st and 2nd upper unicuspids) and to points of the two lower unicuspids (3rd and 4th upper unicuspids). In size the first and second unicuspids are sub-equal and decidedly larger than third, which in turn some- what exceeds fourth. Fifth still smaller than fourth and closely crowded between it and antero-external cusp of large premolar, its cusp relatively lower than in the other teeth of the series. First lower iniicvispid essentially similar to i3rst and second upper, but crown longer than broad and without distinct crushing surface. Second larger than first, not conspicuously different from it in general form when viewed from the side, but cutting edge much longer and better developed, distinctly angled behind middle, the angle clearly i-epresenting a rudimentary second cusp, and transverse portion behind it a second commis- sure, the tooth thus contain- ing the modified elements of one of the triangles of a molar. Large upper pre- molar with protocone smaller than in the first and second molars, though well developed and of essentially the same form ; paracone smaller than pro- tocone, therefore much smaller than in first and second molars ; hypocone small but well developed ; posterior margin of crown more deeply emarginate than that of molars. Crowns of first and second molars squarish in outline, though somewhat wider posteriorly than anteriorly. Outer re-entrant angles deeper in second than i
Size: 1217px × 2054px
Photo credit: © Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookcollectionbiod, bookdecade1910, bookyear1912
