GEOLOGICAL SURVEY OF THE TEREITOEIES. 551 



essentials. The rotular groove is narrow and elevated, the inner margin 

 a little higher. The condyles are rather narrow, the inner with less 

 transverse and antero-posterior extent, and separated by a wide and 

 deep fossa. The patella is narrow, thick, and trnncate at one end. The* 

 proximal end of the tibia exhibits a very prominent and well elevated 

 crest or spine, which bonnds a deeply excavated fossa. The articu- 

 lar faces are separated by a deep notch behind ; the external is a 

 little the larger and is produced into a point outwards and backwards ; 

 it lacks the notch of the antero-exterior margin so distinct in Canis, but 

 possesses an emargination at the outer base of the crest homologous 

 with it. The general form is, however, more like that of Canis than of 

 Felis, and least like that of tfrs^is. The distal extremity of the tibia 

 presents Carnivorous characters. The two trochlear fosspe are deeply 

 impressed, the outer wall of the exteroal one being formed by the fibula 

 only. The anterior marginal crest is more elevated than the posterior, 

 and presents an overlapping articular face betveeen the fossse for a cor- 

 responding tuberosity of the neck of the astragalus. The iuner malleolus 

 is entirely without the groove for the tendon of the tibialis posticus 

 muscle, and therefore different from many of the digitigrade Garnivora. 

 It has an ovate truncate surface. On the anterior face opposite the 

 inner trochlear groove is a rather small but deei) fossa. 



The astragalus has an elongate oblique neck and a navicular extremity 

 slightly expanded inwards. The trochlear ridges are well elevated, and 

 not very oblique to the true vertical plane, being much as in the dog. 

 The distal extremity is quite different from Felis^ Rycena, Canis, and 

 Ursus in having a rather narrow convex facet next the cuboid bone ex- 

 tending from front to rear, and in having the navicular facet pulley-like 

 or slightly concave in tranverse section, "while it is strongly convex 

 antero-posteriorly. This is part of the peculiarity presented by the 

 hind foot in this genus. Behind the navicular facet, on the superior 

 face, is a tuberosity which stops the flexure of the foot by contact with 

 the tibia ; a trace of it is seen in the dog. The calcaneum has the com- 

 pressed form of the digitigrades, but the broader interval, and convex 

 external astragaliue facets resemble much more those in the bears. The 

 cuboid facet is a frustum of a triangle with the apex directed inwards 

 and downwards. 



The metapodial bones are rather elongate, and flattened so as to be 

 transverse in position. A second metatarsal is more flattened than 

 corresponding bones of Canis and Felis. Its cuneiform facet is some- 

 "what concave transversely. The j)halangeal condyles are furnished with 

 an anterior and inferior carina, which is wanting above ; the articular 

 face is wide above as in Canis, and is bounded by a transverse fossa as 

 in digitigrade genera. The phalanges of the first series are elongate 

 and curved as in Felis, being relatively longer than in Ursus. Phalanges 

 of the others series are quite short. The ungues are short and flattened, 

 their inferior surface is nearly plane, and the superior but little convex. 

 A shallow gToove divides the upper face longitudinally to the ex- 

 tremity. The margin below is acute to a slightly contracted neck. 

 There is no indication of collar for reception of the horny sheath, except 

 perhaps a slight area of fracture on each side, and thereisnoln^ojecting 

 tuberosity below for insertion of flexor tendon. The middle of the 

 proxiDDal part of the unguis is a raised plane, and on each side of it, 

 at the neck, two arterial foramina enter. There is a small foramen in the 

 groove, and several smaller ones near the margin. These ungues re- 

 semble somewhat those of some tortoises. They were found with the 

 other phalanges, with which they agree in size and articulation, and uo 



