. On the anatomy of vertebrates [electronic resource] . l remainsof lower jaws and teeth discovered in the oolitic slate at Stones-field, in Oxfordshire, and it receives elucidation from the dentalcharacters of the previous genus, but is remarkable for 225having a still greater number of molar teeth. Thedental formula is as follows : — ?.? ; ?.? ?.? There being thus thirty-two teeth in the lower probably as many in the upper jaw. The following dental formula- . % : c : = 48, characterises a number of Marsupials commonly knownin Australia by the name
. On the anatomy of vertebrates [electronic resource] . l remainsof lower jaws and teeth discovered in the oolitic slate at Stones-field, in Oxfordshire, and it receives elucidation from the dentalcharacters of the previous genus, but is remarkable for 225having a still greater number of molar teeth. Thedental formula is as follows : — ?.? ; ?.? ?.? There being thus thirty-two teeth in the lower probably as many in the upper jaw. The following dental formula- . % : c : = 48, characterises a number of Marsupials commonly knownin Australia by the name of Bandicoots, fig. 226. Theteeth which offer the greatest range of variation in the ^present genus (Perameles) are the external or posterior Mandibular . -I! i T • i • teeth, Myrme- mcisors and the canines: the molars, also, which on- <»miwginally are quinque-cuspidate, have their points worn away, andpresent a smooth and oblique grinding surface in some species(fig. 222, m, vol. ii.) sooner than in others. 288 ANATOMY OF VERTEBRATES. 226. Dentition of Perameles. The Bandicoots which approach nearest to the Myrmecobius inthe condition of the incisive and canine teeth, are the Peramelesobesula and P. Gunnii. There is a slight interval between the firstand second incisor, and the outer or fifth incisor of the upper jawis separated from the rest by an interspace equal to twice its ownbreadth, and moreover presents the triangular pointed canine-likecrown which characterises all the incisors of Myrmecobius ; but the four anterior incisors areplaced close together andhave compressed, quad-rate, true incisive these incisors thecanine is very remote,the interspace beingequally divided by thefifth pointed incisor,which the canine veryslightly exceeds in size. In Peram. nasuta, fig. 226, the incisorspresent the same general condition, but the canines are relativelylarger. The dental formula of the genus Didelphys is— . ;CL1^3^;^4^=50fig-227- The
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