44 University of California Publications in Geology [Vol. 13 



this may indicate relationship with that group. The astragalar facet 

 is less oblique and the concavity not so marked as it is in Enmetopias. 



The dorsal face, in Enmetopias, is very rugose for attachment of 

 ligaments (extensor brevis digitorum), while it is comparatively 

 smooth in our form ; yet this is the longest face in both. A proximal- 

 internal facet articulating with the navicular and a distal articulat- 

 ing with the ecto-cuneiform, are present on the dorsal face. Both 

 facets are longest anteroposteriorly and narrowest transversely. The 

 proximo-internal facet for the navicular or ecto-cuneiform is consider- 

 ably reduced as compared with that of Enmetopias. This facet was 

 probably functional for the navicular but it could hardly have reached 

 the astragalar head. An expansion of the external side of the navicu- 

 lar apparently cut off this facet from contact with the astragalus. 

 The distal facet for the cuneiform is somewhat larger than that in 

 Enmetopias. 



A deep indentation is also present for the attachment of some 

 ligament between the distal facet and the plantar border; in Enme- 

 topias but a trace of it remains. On the plantar face there is a slight 

 groove for the passage of the long peroneal tendon as it passes along 

 the plantar surface of the foot. There is also a blunt, heavy tuberosity 

 for the attachment of muscles. In Enmetopias this peroneal groove 

 is very deep and the tuberosity for the attachment of muscles is 

 greatly developed, extending the whole width of the plantar face. 



Distally, two facets can be distinguished for the articulation with 

 the fourth and fifth metapodials, respectively. These facets are some- 

 what concave in both Enmetopias and this form, but the facets are 

 larger in the latter. Angle between fibular and dorsal faces is much 

 sharper and not so pitted or rugose. 



The fourth metatarsal (fig. 18) probably belongs to some unknown 

 phocid, as it agrees in many respects with that of the fourth meta- 

 tarsal of the right hind limb of Phoca richardii. It differs in the 

 obliquity of the lateral facets on the proximal end of the shaft or 

 base. The internal facet is large and protruding, with margins 



Measurements of Cuboid 



Anteroposterior diameter 



Transverse diameter 



Vertical diameter 



39.4 mm. 

 38.9 mm. 

 57. mm. 



Family Phocidae 

 PHOCID, indet. 



