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Show 374 DR. ST. G. MIVART ON THE ARCTOIDEA. [^Pr- *1» within than without. There are two minute external cusps, a considerably larger internal cusp, and an internal cingulum. The fourth inferior premolar is much like that of Hyana, but with two minute cusps in front of and two behind the large single median cusp. The first lower true molar is sectorial, a good deal like that of the Civets, but with no internal cusp and but a very small talon. The brain l presents a long oblique Sylvian fissure and a Sylvian gyrus, the anterior limb of which is exceedingly narrow. The sagittal gyrus expands very much anteriorly. There is an Ursine lozenge of a rather elongated shape. Helictis2.-This genus contains four species of small more or less arboreal Arctoids from Eastern Asia. The body is elongated aud the limbs short, the tail being either short or of moderate length aud bushy. The ears are small. The snout is elongated, obliquely truncated, and naked at the tip, which bears a distinct nasal groove, whieh extends down the upper lip. The palmar surfaces are naked, but the plantar surfaces are clothed with hair on the hinder half; yet the habit is said to be plantigrade. There are 14 dorsal, 6 lumbar, 3 sacral, and 18 caudal vertebrae. The cranial characters other than those given by Professor Flower3 are that the skull has a rather long muzzle, somewhat like that of Nasua. The occiput shows a marked cerebellar prominence. There are marked postorbital processes from the frontals, but hardly any from the malar bones. The zygomata do not arch strongly outwards. The mastoid process does not descend quite to the level of the floor of the meatus auditorius externus. The palate extends back but little behind the last molars. There is a large infraorbital foramen. The angle of the mandible is formed as in Meles. Molar formula = P. g, M. g. The fourth upper premolar is quite like that of Taxidea4. The first upper true molar diverges from the form met with in the Badger group (i. e. Meles, Taxidea, Arctonyx, and Mydaus), and approaches that found in Procyon. It is like the first upper true molar of Procyon, with the postero-external and postero-internal cusps (especially the latter) reduced in size and with an enlarged internal cingulum. There is also a distinct external cingulum, which tends to develop two small cusps just outside the two external principal cusps. The fourth lower premolar has one principal cusp with a minute accessory cusp in front of it aud two larger ones behind it. The first lower true molar has two external cusps, the hinder one of which slightly predominates. There is also a large internal cusp as 1 See I. c. p. 14, figs. 2 and 3. 2 See Is. Geoff. Voy. de Belang. Zool. p. 129, pi. 5 ; Guerin, Mag. Zool. 1835, vol. l. pi. 14; Horsfield, Zool. Research.; Desm. M a m m . p. 537 ; Cuv. Rech. iv. p. 474 ; Temminck's Monograph, i. p. xx; Hodgson, Journ. Asiatic Soc. of Bengal, v. p. 237, vi. 2, p. 560; Wagner, Supp. ii. p. 201 ; P. Gervais, M a m m . ii. p. 105; Gray, Pr. Zool. Soc. 1833, p. 94, 1853, p. 191,1865, p. 152 ; Cat. Carnivora Brit. Mus. p. 141 ; De Blainville, Osteographie, Mustela. 8 P. Z. S. 1869, p. 12. 4 See above, p. 278. |