232 TEETIAET VEETEBEATA OP THE FATtM. 



The fibular facet {fih.) is nearly flat above, but curved a little outwards towards its 

 antero-inferior border, where it joins the octal facet for the calcaneum is a sharp angle. 

 On the inner side of the trochlea the body of the bone is slightly concave and is 

 produced backwards and inwards into a considerable prominence. 



The neck is long and is directed more inwards than usual in the true Carnivora ; the 

 head bears two facets, a large terminal gently convex surface for the navicular (nav.) and a 

 small surface looking outwards and making an obtuse angle with the last; this (caZ.) is 

 probably for contact with the distal end of the calcaneum or perhaps with the cuboid. 

 The elongated octal facet {ect.) is placed very obliquely to the dorso-plantar axis ; it is 

 slightly concave posteriorly and flat in front. It is sharply bounded on both sides by 

 deep fossa3, that in front separating it from the sustentacular facet and having at its 

 posterior end the ventral opening of the astragalar canal. The sustentacular facet (sm«.) 

 is oval and gently convex ; it appears to be connected with the distal calcaneal facet 

 above noticed by a narrow band. 



The most notable characters of this astragalus seem to be (1) the great extension 

 backwards of the inner half of the tibial surface ; (2) the large size of the astragalar 

 foramen ; (3) the presence of a considerable prominence of the postero-internal angle 

 of the bone. The dimensions (in centimetres) of this bone are : — 



Greatest length 4'4 



„ width 3-7 



"Width of tibial surface 2-4 



M. 9259. Plaster cast of the above specimen. Made in tlie Britisli Museum. 



M. 8441. Left astragalus, imperfect proximally. 



Iff. 8512. Imperfect left calcaneum. The tuber is almost entirely wanting. The octal facet is oblique 

 and elongated ; it is convex posteriorly and flat in front, its outer border being continuous 

 with the small convex fibular facet. The sustentaculum is not very prominent ; it 

 bears an oval concave facet. The cuboid facet is oblique to the long axis of the bone 

 and looks inwards and forwards ; it is very slightly concave. The whole bone seems 

 to have been short and stout. Presented hy W. E. de Winton, Esq., 1903. 



M. 8441a. Imperfect right calcaneum. 



Genus SINOPA, Leidy. 

 [Proc. Acad. Nat. Sci. Philad. 1871, p. 116.] 



1872. Stypoloplius, Cope, Proc. Amer. Phil. Soc. vol. xii. p. 466. 

 1872. Limnocyon (part.). Marsh, Amer. Journ. Sci. [3J vol. iv. p. 126. 



1874. Prototomus, Cope, Report on Vertebrate Fossils obtained by the Wheeler Expedition in New 

 Mexico, p. 13. 



This genus includes small or medium-sized Creodonts, in the mandible of which the 

 first molar is the smallest of the series. The lower molars consist of a high anterior 



