. The cyclopædia of anatomy and physiology. Anatomy; Physiology; Zoology. MAIISUPIALIA, 265 gressively increasing in length as they are placed forward. An interspace occurs between these and the canine, which is long, slender, sharp-pointed, and recurved. The first incisor is longer than the two behind, but is much shorter than the canine. In the lower jaw the true molars are preceded by two functional false ones, similar in size and shape to the three above the anterior false molar, and the canine are represented by minute rudimental simple teeth; the single incisor is long and procumbent as
. The cyclopædia of anatomy and physiology. Anatomy; Physiology; Zoology. MAIISUPIALIA, 265 gressively increasing in length as they are placed forward. An interspace occurs between these and the canine, which is long, slender, sharp-pointed, and recurved. The first incisor is longer than the two behind, but is much shorter than the canine. In the lower jaw the true molars are preceded by two functional false ones, similar in size and shape to the three above the anterior false molar, and the canine are represented by minute rudimental simple teeth; the single incisor is long and procumbent as in the other Petaurists. With these differences of dentition approach- ing more or less to one or other of the modifi- cations of the dentition in the group of Phalan- gers, the Petaurists may nevertheless be readily discriminated from those Phalangers which they most resemble; for example, the PeUturus Taguunoides may be distinguished from the Phalangista Cookii by the greater relative length in the latter of the nasal and maxillary portion of the skull; while in most of the other species of Petaurus, the facial part of the skull is relatively shorter than in the Pet. Tagua- noides. Genus PHASCOLARCTUS. The absence of anomalous or functionless premolars and of inferior canines appears to be constant in the only known species of this genus. The dental formula in three examples of this species ('uscus, Desm.) is o o J J Incisors ; canines ; premo- lars 1—1 1—1 molars 0—0 4—4 : = 30. (Fig. 95.) 1—1 ' 4—4 The true molars are larger in proportion than in the Phalangers; each is beset with four three-sided pyramids, the cusps of which wear down in age, the outer series in the upper teeth being the first to give way ; those of the lower jaw are narrower than those of the upper. The spurious molars are compressed and terminate in a cutting edge; in those of the upper jaw there is a small parallel ridge along the inner side of the base. The canines slightly exceed i
Size: 2331px × 1072px
Photo credit: © Central Historic Books / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bo, booksubjectanatomy, booksubjectphysiology, booksubjectzoology
