GEOLOGICAL SUEVEY OF THE TEREITORIES. 555 



seen in some bears, but the metatarsals are more elongate. The lengths 

 of the latter are, 5th shortest, then 2d, 3d, and 4th. Their condyles 

 are broad, with median keel behind, and shallow supracondylar fossa 

 in front. The first phalanges are about one- third the length of the 

 metacarpals ; the second of digit ^o. 2, broad and stout, and half as 

 long as the phalange of the first row. An ungueal phalange has a 

 singular form, so that the claw might be supposed to have a subungu- 

 late character. It is flat, considerably broader than high, and with ex- 

 panded and obtuse extremity. The articular extremity is depressed and 

 transverse, concave in vertical, convex in transverse section. The an- 

 terior three-fiiths of the superior middle line are occupied by a deep gap- 

 ing fissure, which separates the extremity ipto two points. The inferior 

 face is entirely flat, there being no tendinous tuberosity. The sides are 

 grooved, and give entrance each to a large arterial foramen proximaliy. 

 These claws resemble those of Mesonyx^ and differ remarkably from 

 those of existing terrestrial Carnivora.. 



Of liinder Umh the only characteristic pieces remaining are the navic- 

 ular, cuboid, and an external cuneiform bone. The cuboid is rather 

 stout, with a slight concave facet at one extremity and two at the other, 

 one of them smaller and sublateral. The navicular is wide and flat, and 

 with a strongly concave astragaline facet. Below, it presents two deep 

 oblique concave facets for the cuneiforms, with a small sublateral one on 

 the outer side. The facets of the cuboid and astragalus indicate four 

 well developed digits and another perhaps smaller one. Thus in this 

 genus they were on both limbs probably 5-5, with the inner small. 



The cranium is fractured above. There remain the squamosal and 

 periotic bones, occipital condyles, malar and part of maxillary, both pre- 

 maxillaries and the greater part of both mandibular rami. The post- 

 glenoid process of the squamosal is produced inferiorly far below the 

 auditory meatus, even further than in the bears. Its i^roximal portion 

 includes, on the lower face, a strong groove at right angles to the axis 

 of the cranium, with its defining margins acute and prominent. This is 

 the transverse glenoid cavity of the carnivorous type. The zygoma has 

 a wide curvature indicating a powerful temporal muscle. The posterior 

 angle of the malar extends well posteriorly. Its anterior portion i^ro- 

 jects, forming a longitudinal rib ; there is no produced postorbital pro- 

 cess. The tympanic bone is produced upwards and outwards and forms 

 a tube with everted lips. The opisthotic (mastoid) separates it entirely 

 from the exoccipital, and overlaps the posterior half of the tube by a 

 laminar exj)ansion. A pit in this bone near the meaUis extermis repre- 

 sents the insertion of the stylohyal ligament. There is no bulla, the 

 tympanic chamber being small and with thick walls. The character of 

 this region forbids the idea of any tapiroid affinities on the part of this 

 genus, and resembles that seen in the bears more than that of any other 

 carnivorous type. 



Tho, lyremaxillaries are vertico-oblique in j)osition, presenting thenareal 

 opening directly forwards as in cats, but with a still less prominent 

 alveolar border. The horizontal part of this border is indeed very short, 

 including but two small incisors. It then rises vertically, and turns 

 obliquely backwards to the maxillary, inclosing a deep sinus with the 

 canine tooth. From the anterior side of this sinus th6 larger external 

 incisor issues, with its root extensively exposed externally. A rib 

 ascends from the front of its alveolus to the anterior or nareal margin 

 of the bone. The triturating surfaces of the incisors are directed back- 

 wards, and the alveolar edge is thickened in front of them with a tuber- 

 osity. The teeth are much worn so that the forms of the crowns cannot 



