OCR Text |
Show 384 MR. R. COLLETT O N N E W [May 20, crests are flattened behind1, and converge towards the occipital bone. The nasal bones converge to a common truncated point in the frontals. Fig. 3. Phalangista herbertensis, §. Skull, viewed from the top. Teeth.- Upper jaw. The incisors are three, closely set; the first is large (length from the maxilla 5 millim.), but is only half the length of the first lower incisor; the second and third are small. The canine is separated by a considerable space from the incisors and the first premolar : it is small (of the same size as the second and third incisors). The first premolar small, not larger than the canine; second premolar larger, with 1-2 cusps; third still larger, but not reaching the size of the molars, dilated behind, and with 2-3 cusps. The four molars are large. Lower jaw. The first incisor is very large, its length from the mandible 10 millim., directed horizontally; the second incisor is rudimentary, hardly projecting above the gum, and only visible in the skull. The canine is as rudimentary as the second incisor, and in both skulls only visible on one side. The single premolar situated close to the molars, and of nearly the same size, but wanting the central groove. The molars four ; their series perfectly straight. Dental formula:-m. % p. f, c. \, i. g , c. \, p. \, m. |=38. 1 In the female; the skull of the male is immature. |